001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.lang3.math;
018
019import java.lang.reflect.Array;
020import java.math.BigDecimal;
021import java.math.BigInteger;
022import java.math.RoundingMode;
023import java.util.Objects;
024
025import org.apache.commons.lang3.StringUtils;
026import org.apache.commons.lang3.Validate;
027
028/**
029 * Provides extra functionality for Java Number classes.
030 *
031 * @since 2.0
032 */
033public class NumberUtils {
034
035    /** Reusable Long constant for zero. */
036    public static final Long LONG_ZERO = Long.valueOf(0L);
037    /** Reusable Long constant for one. */
038    public static final Long LONG_ONE = Long.valueOf(1L);
039    /** Reusable Long constant for minus one. */
040    public static final Long LONG_MINUS_ONE = Long.valueOf(-1L);
041    /** Reusable Integer constant for zero. */
042    public static final Integer INTEGER_ZERO = Integer.valueOf(0);
043    /** Reusable Integer constant for one. */
044    public static final Integer INTEGER_ONE = Integer.valueOf(1);
045    /** Reusable Integer constant for two */
046    public static final Integer INTEGER_TWO = Integer.valueOf(2);
047    /** Reusable Integer constant for minus one. */
048    public static final Integer INTEGER_MINUS_ONE = Integer.valueOf(-1);
049    /** Reusable Short constant for zero. */
050    public static final Short SHORT_ZERO = Short.valueOf((short) 0);
051    /** Reusable Short constant for one. */
052    public static final Short SHORT_ONE = Short.valueOf((short) 1);
053    /** Reusable Short constant for minus one. */
054    public static final Short SHORT_MINUS_ONE = Short.valueOf((short) -1);
055    /** Reusable Byte constant for zero. */
056    public static final Byte BYTE_ZERO = Byte.valueOf((byte) 0);
057    /** Reusable Byte constant for one. */
058    public static final Byte BYTE_ONE = Byte.valueOf((byte) 1);
059    /** Reusable Byte constant for minus one. */
060    public static final Byte BYTE_MINUS_ONE = Byte.valueOf((byte) -1);
061    /** Reusable Double constant for zero. */
062    public static final Double DOUBLE_ZERO = Double.valueOf(0.0d);
063    /** Reusable Double constant for one. */
064    public static final Double DOUBLE_ONE = Double.valueOf(1.0d);
065    /** Reusable Double constant for minus one. */
066    public static final Double DOUBLE_MINUS_ONE = Double.valueOf(-1.0d);
067    /** Reusable Float constant for zero. */
068    public static final Float FLOAT_ZERO = Float.valueOf(0.0f);
069    /** Reusable Float constant for one. */
070    public static final Float FLOAT_ONE = Float.valueOf(1.0f);
071    /** Reusable Float constant for minus one. */
072    public static final Float FLOAT_MINUS_ONE = Float.valueOf(-1.0f);
073
074    /**
075     * {@link Integer#MAX_VALUE} as a {@link Long}.
076     *
077     * @since 3.12.0
078     */
079    public static final Long LONG_INT_MAX_VALUE = Long.valueOf(Integer.MAX_VALUE);
080
081    /**
082     * {@link Integer#MIN_VALUE} as a {@link Long}.
083     *
084     * @since 3.12.0
085     */
086    public static final Long LONG_INT_MIN_VALUE = Long.valueOf(Integer.MIN_VALUE);
087
088    /**
089     * Compares two {@code byte} values numerically. This is the same functionality as provided in Java 7.
090     *
091     * @param x the first {@code byte} to compare
092     * @param y the second {@code byte} to compare
093     * @return the value {@code 0} if {@code x == y};
094     *         a value less than {@code 0} if {@code x < y}; and
095     *         a value greater than {@code 0} if {@code x > y}
096     * @since 3.4
097     */
098    public static int compare(final byte x, final byte y) {
099        return x - y;
100    }
101
102    /**
103     * Compares two {@code int} values numerically. This is the same functionality as provided in Java 7.
104     *
105     * @param x the first {@code int} to compare
106     * @param y the second {@code int} to compare
107     * @return the value {@code 0} if {@code x == y};
108     *         a value less than {@code 0} if {@code x < y}; and
109     *         a value greater than {@code 0} if {@code x > y}
110     * @since 3.4
111     */
112    public static int compare(final int x, final int y) {
113        if (x == y) {
114            return 0;
115        }
116        return x < y ? -1 : 1;
117    }
118
119    /**
120     * Compares to {@code long} values numerically. This is the same functionality as provided in Java 7.
121     *
122     * @param x the first {@code long} to compare
123     * @param y the second {@code long} to compare
124     * @return the value {@code 0} if {@code x == y};
125     *         a value less than {@code 0} if {@code x < y}; and
126     *         a value greater than {@code 0} if {@code x > y}
127     * @since 3.4
128     */
129    public static int compare(final long x, final long y) {
130        if (x == y) {
131            return 0;
132        }
133        return x < y ? -1 : 1;
134    }
135
136    /**
137     * Compares to {@code short} values numerically. This is the same functionality as provided in Java 7.
138     *
139     * @param x the first {@code short} to compare
140     * @param y the second {@code short} to compare
141     * @return the value {@code 0} if {@code x == y};
142     *         a value less than {@code 0} if {@code x < y}; and
143     *         a value greater than {@code 0} if {@code x > y}
144     * @since 3.4
145     */
146    public static int compare(final short x, final short y) {
147        if (x == y) {
148            return 0;
149        }
150        return x < y ? -1 : 1;
151    }
152
153    /**
154     * Creates a {@link BigDecimal} from a {@link String}.
155     *
156     * <p>Returns {@code null} if the string is {@code null}.</p>
157     *
158     * @param str  a {@link String} to convert, may be null
159     * @return converted {@link BigDecimal} (or null if the input is null)
160     * @throws NumberFormatException if the value cannot be converted
161     */
162    public static BigDecimal createBigDecimal(final String str) {
163        if (str == null) {
164            return null;
165        }
166        // handle JDK1.3.1 bug where "" throws IndexOutOfBoundsException
167        if (StringUtils.isBlank(str)) {
168            throw new NumberFormatException("A blank string is not a valid number");
169        }
170        return new BigDecimal(str);
171    }
172
173    /**
174     * Creates a {@link BigInteger} from a {@link String}.
175     *
176     * Handles hexadecimal (0x or #) and octal (0) notations.
177     *
178     * <p>Returns {@code null} if the string is {@code null}.</p>
179     *
180     * @param str  a {@link String} to convert, may be null
181     * @return converted {@link BigInteger} (or null if the input is null)
182     * @throws NumberFormatException if the value cannot be converted
183     * @since 3.2
184     */
185    public static BigInteger createBigInteger(final String str) {
186        if (str == null) {
187            return null;
188        }
189        if (str.isEmpty()) {
190            throw new NumberFormatException("An empty string is not a valid number");
191        }
192        int pos = 0; // offset within string
193        int radix = 10;
194        boolean negate = false; // need to negate later?
195        final char char0 = str.charAt(0);
196        if (char0 == '-') {
197            negate = true;
198            pos = 1;
199        } else if (char0 == '+') {
200            pos = 1;
201        }
202        if (str.startsWith("0x", pos) || str.startsWith("0X", pos)) { // hex
203            radix = 16;
204            pos += 2;
205        } else if (str.startsWith("#", pos)) { // alternative hex (allowed by Long/Integer)
206            radix = 16;
207            pos++;
208        } else if (str.startsWith("0", pos) && str.length() > pos + 1) { // octal; so long as there are additional digits
209            radix = 8;
210            pos++;
211        } // default is to treat as decimal
212
213        final BigInteger value = new BigInteger(str.substring(pos), radix);
214        return negate ? value.negate() : value;
215    }
216
217    /**
218     * Creates a {@link Double} from a {@link String}.
219     *
220     * <p>Returns {@code null} if the string is {@code null}.</p>
221     *
222     * @param str  a {@link String} to convert, may be null
223     * @return converted {@link Double} (or null if the input is null)
224     * @throws NumberFormatException if the value cannot be converted
225     */
226    public static Double createDouble(final String str) {
227        if (str == null) {
228            return null;
229        }
230        return Double.valueOf(str);
231    }
232
233    /**
234     * Creates a {@link Float} from a {@link String}.
235     *
236     * <p>Returns {@code null} if the string is {@code null}.</p>
237     *
238     * @param str  a {@link String} to convert, may be null
239     * @return converted {@link Float} (or null if the input is null)
240     * @throws NumberFormatException if the value cannot be converted
241     */
242    public static Float createFloat(final String str) {
243        if (str == null) {
244            return null;
245        }
246        return Float.valueOf(str);
247    }
248
249    /**
250     * Creates an {@link Integer} from a {@link String}.
251     *
252     * Handles hexadecimal (0xhhhh) and octal (0dddd) notations.
253     * N.B. a leading zero means octal; spaces are not trimmed.
254     *
255     * <p>Returns {@code null} if the string is {@code null}.</p>
256     *
257     * @param str  a {@link String} to convert, may be null
258     * @return converted {@link Integer} (or null if the input is null)
259     * @throws NumberFormatException if the value cannot be converted
260     */
261    public static Integer createInteger(final String str) {
262        if (str == null) {
263            return null;
264        }
265        // decode() handles 0xAABD and 0777 (hex and octal) as well.
266        return Integer.decode(str);
267    }
268
269    /**
270     * Creates a {@link Long} from a {@link String}.
271     *
272     * Handles hexadecimal (0Xhhhh) and octal (0ddd) notations.
273     * N.B. a leading zero means octal; spaces are not trimmed.
274     *
275     * <p>Returns {@code null} if the string is {@code null}.</p>
276     *
277     * @param str  a {@link String} to convert, may be null
278     * @return converted {@link Long} (or null if the input is null)
279     * @throws NumberFormatException if the value cannot be converted
280     * @since 3.1
281     */
282    public static Long createLong(final String str) {
283        if (str == null) {
284            return null;
285        }
286        return Long.decode(str);
287    }
288
289    /**
290     * Creates a {@link Number} from a {@link String}.
291     *
292     * <p>If the string starts with {@code 0x} or {@code -0x} (lower or upper case) or {@code #} or {@code -#}, it
293     * will be interpreted as a hexadecimal Integer - or Long, if the number of digits after the
294     * prefix is more than 8 - or BigInteger if there are more than 16 digits.
295     * </p>
296     * <p>Then, the value is examined for a type qualifier on the end, i.e. one of
297     * {@code 'f', 'F', 'd', 'D', 'l', 'L'}.  If it is found, it starts
298     * trying to create successively larger types from the type specified
299     * until one is found that can represent the value.</p>
300     *
301     * <p>If a type specifier is not found, it will check for a decimal point
302     * and then try successively larger types from {@link Integer} to
303     * {@link BigInteger} and from {@link Float} to
304     * {@link BigDecimal}.</p>
305     *
306     * <p>
307     * Integral values with a leading {@code 0} will be interpreted as octal; the returned number will
308     * be Integer, Long or BigDecimal as appropriate.
309     * </p>
310     *
311     * <p>Returns {@code null} if the string is {@code null}.</p>
312     *
313     * <p>This method does not trim the input string, i.e., strings with leading
314     * or trailing spaces will generate NumberFormatExceptions.</p>
315     *
316     * @param str  String containing a number, may be null
317     * @return Number created from the string (or null if the input is null)
318     * @throws NumberFormatException if the value cannot be converted
319     */
320    public static Number createNumber(final String str) {
321        if (str == null) {
322            return null;
323        }
324        if (StringUtils.isBlank(str)) {
325            throw new NumberFormatException("A blank string is not a valid number");
326        }
327        // Need to deal with all possible hex prefixes here
328        final String[] hexPrefixes = {"0x", "0X", "#"};
329        final int length = str.length();
330        final int offset = str.charAt(0) == '+' || str.charAt(0) == '-' ? 1 : 0;
331        int pfxLen = 0;
332        for (final String pfx : hexPrefixes) {
333            if (str.startsWith(pfx, offset)) {
334                pfxLen += pfx.length() + offset;
335                break;
336            }
337        }
338        if (pfxLen > 0) { // we have a hex number
339            char firstSigDigit = 0; // strip leading zeroes
340            for (int i = pfxLen; i < length; i++) {
341                firstSigDigit = str.charAt(i);
342                if (firstSigDigit != '0') {
343                    break;
344                }
345                pfxLen++;
346            }
347            final int hexDigits = length - pfxLen;
348            if (hexDigits > 16 || hexDigits == 16 && firstSigDigit > '7') { // too many for Long
349                return createBigInteger(str);
350            }
351            if (hexDigits > 8 || hexDigits == 8 && firstSigDigit > '7') { // too many for an int
352                return createLong(str);
353            }
354            return createInteger(str);
355        }
356        final char lastChar = str.charAt(length - 1);
357        final String mant;
358        final String dec;
359        final String exp;
360        final int decPos = str.indexOf('.');
361        final int expPos = str.indexOf('e') + str.indexOf('E') + 1; // assumes both not present
362        // if both e and E are present, this is caught by the checks on expPos (which prevent IOOBE)
363        // and the parsing which will detect if e or E appear in a number due to using the wrong offset
364
365        // Detect if the return type has been requested
366        final boolean requestType = !Character.isDigit(lastChar) && lastChar != '.';
367        if (decPos > -1) { // there is a decimal point
368            if (expPos > -1) { // there is an exponent
369                if (expPos <= decPos || expPos > length) { // prevents double exponent causing IOOBE
370                    throw new NumberFormatException(str + " is not a valid number.");
371                }
372                dec = str.substring(decPos + 1, expPos);
373            } else {
374                // No exponent, but there may be a type character to remove
375                dec = str.substring(decPos + 1, requestType ? length - 1 : length);
376            }
377            mant = getMantissa(str, decPos);
378        } else {
379            if (expPos > -1) {
380                if (expPos > length) { // prevents double exponent causing IOOBE
381                    throw new NumberFormatException(str + " is not a valid number.");
382                }
383                mant = getMantissa(str, expPos);
384            } else {
385                // No decimal, no exponent, but there may be a type character to remove
386                mant = getMantissa(str, requestType ? length - 1 : length);
387            }
388            dec = null;
389        }
390        if (requestType) {
391            if (expPos > -1 && expPos < length - 1) {
392                exp = str.substring(expPos + 1, length - 1);
393            } else {
394                exp = null;
395            }
396            //Requesting a specific type.
397            final String numeric = str.substring(0, length - 1);
398            switch (lastChar) {
399                case 'l' :
400                case 'L' :
401                    if (dec == null
402                        && exp == null
403                        && (!numeric.isEmpty() && numeric.charAt(0) == '-' && isDigits(numeric.substring(1)) || isDigits(numeric))) {
404                        try {
405                            return createLong(numeric);
406                        } catch (final NumberFormatException ignored) {
407                            // Too big for a long
408                        }
409                        return createBigInteger(numeric);
410
411                    }
412                    throw new NumberFormatException(str + " is not a valid number.");
413                case 'f' :
414                case 'F' :
415                    try {
416                        final Float f = createFloat(str);
417                        if (!(f.isInfinite() || f.floatValue() == 0.0F && !isZero(mant, dec))) {
418                            //If it's too big for a float or the float value = 0 and the string
419                            //has non-zeros in it, then float does not have the precision we want
420                            return f;
421                        }
422
423                    } catch (final NumberFormatException ignored) {
424                        // ignore the bad number
425                    }
426                    //$FALL-THROUGH$
427                case 'd' :
428                case 'D' :
429                    try {
430                        final Double d = createDouble(str);
431                        if (!(d.isInfinite() || d.doubleValue() == 0.0D && !isZero(mant, dec))) {
432                            return d;
433                        }
434                    } catch (final NumberFormatException ignored) {
435                        // ignore the bad number
436                    }
437                    try {
438                        return createBigDecimal(numeric);
439                    } catch (final NumberFormatException ignored) {
440                        // ignore the bad number
441                    }
442                    //$FALL-THROUGH$
443                default :
444                    throw new NumberFormatException(str + " is not a valid number.");
445
446            }
447        }
448        //User doesn't have a preference on the return type, so let's start
449        //small and go from there...
450        if (expPos > -1 && expPos < length - 1) {
451            exp = str.substring(expPos + 1);
452        } else {
453            exp = null;
454        }
455        if (dec == null && exp == null) { // no decimal point and no exponent
456            //Must be an Integer, Long, Biginteger
457            try {
458                return createInteger(str);
459            } catch (final NumberFormatException ignored) {
460                // ignore the bad number
461            }
462            try {
463                return createLong(str);
464            } catch (final NumberFormatException ignored) {
465                // ignore the bad number
466            }
467            return createBigInteger(str);
468        }
469
470        //Must be a Float, Double, BigDecimal
471        try {
472            final Float f = createFloat(str);
473            final Double d = createDouble(str);
474            if (!f.isInfinite()
475                    && !(f.floatValue() == 0.0F && !isZero(mant, dec))
476                    && f.toString().equals(d.toString())) {
477                return f;
478            }
479            if (!d.isInfinite() && !(d.doubleValue() == 0.0D && !isZero(mant, dec))) {
480                final BigDecimal b = createBigDecimal(str);
481                if (b.compareTo(BigDecimal.valueOf(d.doubleValue())) == 0) {
482                    return d;
483                }
484                return b;
485            }
486        } catch (final NumberFormatException ignored) {
487            // ignore the bad number
488        }
489        return createBigDecimal(str);
490    }
491
492     /**
493     * Utility method for {@link #createNumber(String)}.
494     *
495     * <p>Returns mantissa of the given number.</p>
496     *
497     * @param str the string representation of the number
498     * @param stopPos the position of the exponent or decimal point
499     * @return mantissa of the given number
500     * @throws NumberFormatException if no mantissa can be retrieved
501     */
502    private static String getMantissa(final String str, final int stopPos) {
503         final char firstChar = str.charAt(0);
504         final boolean hasSign = firstChar == '-' || firstChar == '+';
505         final int length = str.length();
506         if (length <= (hasSign ? 1 : 0) || length < stopPos) {
507             throw new NumberFormatException(str + " is not a valid number.");
508         }
509         return hasSign ? str.substring(1, stopPos) : str.substring(0, stopPos);
510    }
511
512    /**
513     * Utility method for {@link #createNumber(java.lang.String)}.
514     *
515     * <p>Returns {@code true} if s is {@code null} or empty.</p>
516     *
517     * @param str the String to check
518     * @return if it is all zeros or {@code null}
519     */
520    private static boolean isAllZeros(final String str) {
521        if (str == null) {
522            return true;
523        }
524        for (int i = str.length() - 1; i >= 0; i--) {
525            if (str.charAt(i) != '0') {
526                return false;
527            }
528        }
529        return true;
530    }
531
532    /**
533     * Checks whether the String is a valid Java number.
534     *
535     * <p>Valid numbers include hexadecimal marked with the {@code 0x} or
536     * {@code 0X} qualifier, octal numbers, scientific notation and
537     * numbers marked with a type qualifier (e.g. 123L).</p>
538     *
539     * <p>Non-hexadecimal strings beginning with a leading zero are
540     * treated as octal values. Thus the string {@code 09} will return
541     * {@code false}, since {@code 9} is not a valid octal value.
542     * However, numbers beginning with {@code 0.} are treated as decimal.</p>
543     *
544     * <p>{@code null} and empty/blank {@link String} will return
545     * {@code false}.</p>
546     *
547     * <p>Note, {@link #createNumber(String)} should return a number for every
548     * input resulting in {@code true}.</p>
549     *
550     * @param str  the {@link String} to check
551     * @return {@code true} if the string is a correctly formatted number
552     * @since 3.5
553     */
554    public static boolean isCreatable(final String str) {
555        if (StringUtils.isEmpty(str)) {
556            return false;
557        }
558        final char[] chars = str.toCharArray();
559        int sz = chars.length;
560        boolean hasExp = false;
561        boolean hasDecPoint = false;
562        boolean allowSigns = false;
563        boolean foundDigit = false;
564        // deal with any possible sign up front
565        final int start = chars[0] == '-' || chars[0] == '+' ? 1 : 0;
566        if (sz > start + 1 && chars[start] == '0' && !StringUtils.contains(str, '.')) { // leading 0, skip if is a decimal number
567            if (chars[start + 1] == 'x' || chars[start + 1] == 'X') { // leading 0x/0X
568                int i = start + 2;
569                if (i == sz) {
570                    return false; // str == "0x"
571                }
572                // checking hex (it can't be anything else)
573                for (; i < chars.length; i++) {
574                    if ((chars[i] < '0' || chars[i] > '9')
575                        && (chars[i] < 'a' || chars[i] > 'f')
576                        && (chars[i] < 'A' || chars[i] > 'F')) {
577                        return false;
578                    }
579                }
580                return true;
581           }
582            if (Character.isDigit(chars[start + 1])) {
583                   // leading 0, but not hex, must be octal
584                   int i = start + 1;
585                   for (; i < chars.length; i++) {
586                       if (chars[i] < '0' || chars[i] > '7') {
587                           return false;
588                       }
589                   }
590                   return true;
591               }
592        }
593        sz--; // don't want to loop to the last char, check it afterwards
594              // for type qualifiers
595        int i = start;
596        // loop to the next to last char or to the last char if we need another digit to
597        // make a valid number (e.g. chars[0..5] = "1234E")
598        while (i < sz || i < sz + 1 && allowSigns && !foundDigit) {
599            if (chars[i] >= '0' && chars[i] <= '9') {
600                foundDigit = true;
601                allowSigns = false;
602
603            } else if (chars[i] == '.') {
604                if (hasDecPoint || hasExp) {
605                    // two decimal points or dec in exponent
606                    return false;
607                }
608                hasDecPoint = true;
609            } else if (chars[i] == 'e' || chars[i] == 'E') {
610                // we've already taken care of hex.
611                if (hasExp) {
612                    // two E's
613                    return false;
614                }
615                if (!foundDigit) {
616                    return false;
617                }
618                hasExp = true;
619                allowSigns = true;
620            } else if (chars[i] == '+' || chars[i] == '-') {
621                if (!allowSigns) {
622                    return false;
623                }
624                allowSigns = false;
625                foundDigit = false; // we need a digit after the E
626            } else {
627                return false;
628            }
629            i++;
630        }
631        if (i < chars.length) {
632            if (chars[i] >= '0' && chars[i] <= '9') {
633                // no type qualifier, OK
634                return true;
635            }
636            if (chars[i] == 'e' || chars[i] == 'E') {
637                // can't have an E at the last byte
638                return false;
639            }
640            if (chars[i] == '.') {
641                if (hasDecPoint || hasExp) {
642                    // two decimal points or dec in exponent
643                    return false;
644                }
645                // single trailing decimal point after non-exponent is ok
646                return foundDigit;
647            }
648            if (!allowSigns
649                && (chars[i] == 'd'
650                    || chars[i] == 'D'
651                    || chars[i] == 'f'
652                    || chars[i] == 'F')) {
653                return foundDigit;
654            }
655            if (chars[i] == 'l'
656                || chars[i] == 'L') {
657                // not allowing L with an exponent or decimal point
658                return foundDigit && !hasExp && !hasDecPoint;
659            }
660            // last character is illegal
661            return false;
662        }
663        // allowSigns is true iff the val ends in 'E'
664        // found digit it to make sure weird stuff like '.' and '1E-' doesn't pass
665        return !allowSigns && foundDigit;
666    }
667
668    /**
669     * Checks whether the {@link String} contains only
670     * digit characters.
671     *
672     * <p>{@code null} and empty String will return
673     * {@code false}.</p>
674     *
675     * @param str  the {@link String} to check
676     * @return {@code true} if str contains only Unicode numeric
677     */
678    public static boolean isDigits(final String str) {
679        return StringUtils.isNumeric(str);
680    }
681
682    /**
683     * Checks whether the String is a valid Java number.
684     *
685     * <p>Valid numbers include hexadecimal marked with the {@code 0x} or
686     * {@code 0X} qualifier, octal numbers, scientific notation and
687     * numbers marked with a type qualifier (e.g. 123L).</p>
688     *
689     * <p>Non-hexadecimal strings beginning with a leading zero are
690     * treated as octal values. Thus the string {@code 09} will return
691     * {@code false}, since {@code 9} is not a valid octal value.
692     * However, numbers beginning with {@code 0.} are treated as decimal.</p>
693     *
694     * <p>{@code null} and empty/blank {@link String} will return
695     * {@code false}.</p>
696     *
697     * <p>Note, {@link #createNumber(String)} should return a number for every
698     * input resulting in {@code true}.</p>
699     *
700     * @param str  the {@link String} to check
701     * @return {@code true} if the string is a correctly formatted number
702     * @since 3.3 the code supports hexadecimal {@code 0Xhhh} an
703     *        octal {@code 0ddd} validation
704     * @deprecated This feature will be removed in Lang 4,
705     *             use {@link NumberUtils#isCreatable(String)} instead
706     */
707    @Deprecated
708    public static boolean isNumber(final String str) {
709        return isCreatable(str);
710    }
711
712    /**
713     * Checks whether the given String is a parsable number.
714     *
715     * <p>Parsable numbers include those Strings understood by {@link Integer#parseInt(String)},
716     * {@link Long#parseLong(String)}, {@link Float#parseFloat(String)} or
717     * {@link Double#parseDouble(String)}. This method can be used instead of catching {@link java.text.ParseException}
718     * when calling one of those methods.</p>
719     *
720     * <p>Hexadecimal and scientific notations are <strong>not</strong> considered parsable.
721     * See {@link #isCreatable(String)} on those cases.</p>
722     *
723     * <p>{@code null} and empty String will return {@code false}.</p>
724     *
725     * @param str the String to check.
726     * @return {@code true} if the string is a parsable number.
727     * @since 3.4
728     */
729    public static boolean isParsable(final String str) {
730        if (StringUtils.isEmpty(str)) {
731            return false;
732        }
733        if (str.charAt(str.length() - 1) == '.') {
734            return false;
735        }
736        if (str.charAt(0) == '-') {
737            if (str.length() == 1) {
738                return false;
739            }
740            return withDecimalsParsing(str, 1);
741        }
742        return withDecimalsParsing(str, 0);
743    }
744
745    /**
746     * Utility method for {@link #createNumber(java.lang.String)}.
747     *
748     * <p>This will check if the magnitude of the number is zero by checking if there
749     * are only zeros before and after the decimal place.</p>
750     *
751     * <p>Note: It is <strong>assumed</strong> that the input string has been converted
752     * to either a Float or Double with a value of zero when this method is called.
753     * This eliminates invalid input for example {@code ".", ".D", ".e0"}.</p>
754     *
755     * <p>Thus the method only requires checking if both arguments are null, empty or
756     * contain only zeros.</p>
757     *
758     * <p>Given {@code s = mant + "." + dec}:</p>
759     * <ul>
760     * <li>{@code true} if s is {@code "0.0"}
761     * <li>{@code true} if s is {@code "0."}
762     * <li>{@code true} if s is {@code ".0"}
763     * <li>{@code false} otherwise (this assumes {@code "."} is not possible)
764     * </ul>
765     *
766     * @param mant the mantissa decimal digits before the decimal point (sign must be removed; never null)
767     * @param dec the decimal digits after the decimal point (exponent and type specifier removed;
768     *            can be null)
769     * @return true if the magnitude is zero
770     */
771    private static boolean isZero(final String mant, final String dec) {
772        return isAllZeros(mant) && isAllZeros(dec);
773    }
774
775    /**
776     * Returns the maximum value in an array.
777     *
778     * @param array  an array, must not be null or empty
779     * @return the maximum value in the array
780     * @throws NullPointerException if {@code array} is {@code null}
781     * @throws IllegalArgumentException if {@code array} is empty
782     * @since 3.4 Changed signature from max(byte[]) to max(byte...)
783     */
784    public static byte max(final byte... array) {
785        // Validates input
786        validateArray(array);
787
788        // Finds and returns max
789        byte max = array[0];
790        for (int i = 1; i < array.length; i++) {
791            if (array[i] > max) {
792                max = array[i];
793            }
794        }
795
796        return max;
797    }
798
799    /**
800     * Gets the maximum of three {@code byte} values.
801     *
802     * @param a  value 1
803     * @param b  value 2
804     * @param c  value 3
805     * @return  the largest of the values
806     */
807    public static byte max(byte a, final byte b, final byte c) {
808        if (b > a) {
809            a = b;
810        }
811        if (c > a) {
812            a = c;
813        }
814        return a;
815    }
816
817    /**
818     * Returns the maximum value in an array.
819     *
820     * @param array  an array, must not be null or empty
821     * @return the maximum value in the array
822     * @throws NullPointerException if {@code array} is {@code null}
823     * @throws IllegalArgumentException if {@code array} is empty
824     * @see IEEE754rUtils#max(double[]) IEEE754rUtils for a version of this method that handles NaN differently
825     * @since 3.4 Changed signature from max(double[]) to max(double...)
826     */
827    public static double max(final double... array) {
828        // Validates input
829        validateArray(array);
830
831        // Finds and returns max
832        double max = array[0];
833        for (int j = 1; j < array.length; j++) {
834            if (Double.isNaN(array[j])) {
835                return Double.NaN;
836            }
837            if (array[j] > max) {
838                max = array[j];
839            }
840        }
841
842        return max;
843    }
844
845    /**
846     * Gets the maximum of three {@code double} values.
847     *
848     * <p>If any value is {@code NaN}, {@code NaN} is
849     * returned. Infinity is handled.</p>
850     *
851     * @param a  value 1
852     * @param b  value 2
853     * @param c  value 3
854     * @return  the largest of the values
855     * @see IEEE754rUtils#max(double, double, double) for a version of this method that handles NaN differently
856     */
857    public static double max(final double a, final double b, final double c) {
858        return Math.max(Math.max(a, b), c);
859    }
860
861    /**
862     * Returns the maximum value in an array.
863     *
864     * @param array  an array, must not be null or empty
865     * @return the maximum value in the array
866     * @throws NullPointerException if {@code array} is {@code null}
867     * @throws IllegalArgumentException if {@code array} is empty
868     * @see IEEE754rUtils#max(float[]) IEEE754rUtils for a version of this method that handles NaN differently
869     * @since 3.4 Changed signature from max(float[]) to max(float...)
870     */
871    public static float max(final float... array) {
872        // Validates input
873        validateArray(array);
874
875        // Finds and returns max
876        float max = array[0];
877        for (int j = 1; j < array.length; j++) {
878            if (Float.isNaN(array[j])) {
879                return Float.NaN;
880            }
881            if (array[j] > max) {
882                max = array[j];
883            }
884        }
885
886        return max;
887    }
888
889    // must handle Long, Float, Integer, Float, Short,
890    //                  BigDecimal, BigInteger and Byte
891    // useful methods:
892    // Byte.decode(String)
893    // Byte.valueOf(String, int radix)
894    // Byte.valueOf(String)
895    // Double.valueOf(String)
896    // Float.valueOf(String)
897    // Float.valueOf(String)
898    // Integer.valueOf(String, int radix)
899    // Integer.valueOf(String)
900    // Integer.decode(String)
901    // Integer.getInteger(String)
902    // Integer.getInteger(String, int val)
903    // Integer.getInteger(String, Integer val)
904    // Integer.valueOf(String)
905    // Double.valueOf(String)
906    // new Byte(String)
907    // Long.valueOf(String)
908    // Long.getLong(String)
909    // Long.getLong(String, int)
910    // Long.getLong(String, Integer)
911    // Long.valueOf(String, int)
912    // Long.valueOf(String)
913    // Short.valueOf(String)
914    // Short.decode(String)
915    // Short.valueOf(String, int)
916    // Short.valueOf(String)
917    // new BigDecimal(String)
918    // new BigInteger(String)
919    // new BigInteger(String, int radix)
920    // Possible inputs:
921    // 45 45.5 45E7 4.5E7 Hex Oct Binary xxxF xxxD xxxf xxxd
922    // plus minus everything. Prolly more. A lot are not separable.
923
924    /**
925     * Gets the maximum of three {@code float} values.
926     *
927     * <p>If any value is {@code NaN}, {@code NaN} is
928     * returned. Infinity is handled.</p>
929     *
930     * @param a  value 1
931     * @param b  value 2
932     * @param c  value 3
933     * @return  the largest of the values
934     * @see IEEE754rUtils#max(float, float, float) for a version of this method that handles NaN differently
935     */
936    public static float max(final float a, final float b, final float c) {
937        return Math.max(Math.max(a, b), c);
938    }
939
940    /**
941     * Returns the maximum value in an array.
942     *
943     * @param array  an array, must not be null or empty
944     * @return the maximum value in the array
945     * @throws NullPointerException if {@code array} is {@code null}
946     * @throws IllegalArgumentException if {@code array} is empty
947     * @since 3.4 Changed signature from max(int[]) to max(int...)
948     */
949    public static int max(final int... array) {
950        // Validates input
951        validateArray(array);
952
953        // Finds and returns max
954        int max = array[0];
955        for (int j = 1; j < array.length; j++) {
956            if (array[j] > max) {
957                max = array[j];
958            }
959        }
960
961        return max;
962    }
963
964    /**
965     * Gets the maximum of three {@code int} values.
966     *
967     * @param a  value 1
968     * @param b  value 2
969     * @param c  value 3
970     * @return  the largest of the values
971     */
972    public static int max(int a, final int b, final int c) {
973        if (b > a) {
974            a = b;
975        }
976        if (c > a) {
977            a = c;
978        }
979        return a;
980    }
981
982    /**
983     * Returns the maximum value in an array.
984     *
985     * @param array  an array, must not be null or empty
986     * @return the maximum value in the array
987     * @throws NullPointerException if {@code array} is {@code null}
988     * @throws IllegalArgumentException if {@code array} is empty
989     * @since 3.4 Changed signature from max(long[]) to max(long...)
990     */
991    public static long max(final long... array) {
992        // Validates input
993        validateArray(array);
994
995        // Finds and returns max
996        long max = array[0];
997        for (int j = 1; j < array.length; j++) {
998            if (array[j] > max) {
999                max = array[j];
1000            }
1001        }
1002
1003        return max;
1004    }
1005
1006    // 3 param max
1007    /**
1008     * Gets the maximum of three {@code long} values.
1009     *
1010     * @param a  value 1
1011     * @param b  value 2
1012     * @param c  value 3
1013     * @return  the largest of the values
1014     */
1015    public static long max(long a, final long b, final long c) {
1016        if (b > a) {
1017            a = b;
1018        }
1019        if (c > a) {
1020            a = c;
1021        }
1022        return a;
1023    }
1024
1025    /**
1026     * Returns the maximum value in an array.
1027     *
1028     * @param array  an array, must not be null or empty
1029     * @return the maximum value in the array
1030     * @throws NullPointerException if {@code array} is {@code null}
1031     * @throws IllegalArgumentException if {@code array} is empty
1032     * @since 3.4 Changed signature from max(short[]) to max(short...)
1033     */
1034    public static short max(final short... array) {
1035        // Validates input
1036        validateArray(array);
1037
1038        // Finds and returns max
1039        short max = array[0];
1040        for (int i = 1; i < array.length; i++) {
1041            if (array[i] > max) {
1042                max = array[i];
1043            }
1044        }
1045
1046        return max;
1047    }
1048
1049    /**
1050     * Gets the maximum of three {@code short} values.
1051     *
1052     * @param a  value 1
1053     * @param b  value 2
1054     * @param c  value 3
1055     * @return  the largest of the values
1056     */
1057    public static short max(short a, final short b, final short c) {
1058        if (b > a) {
1059            a = b;
1060        }
1061        if (c > a) {
1062            a = c;
1063        }
1064        return a;
1065    }
1066
1067    /**
1068     * Returns the minimum value in an array.
1069     *
1070     * @param array  an array, must not be null or empty
1071     * @return the minimum value in the array
1072     * @throws NullPointerException if {@code array} is {@code null}
1073     * @throws IllegalArgumentException if {@code array} is empty
1074     * @since 3.4 Changed signature from min(byte[]) to min(byte...)
1075     */
1076    public static byte min(final byte... array) {
1077        // Validates input
1078        validateArray(array);
1079
1080        // Finds and returns min
1081        byte min = array[0];
1082        for (int i = 1; i < array.length; i++) {
1083            if (array[i] < min) {
1084                min = array[i];
1085            }
1086        }
1087
1088        return min;
1089    }
1090
1091    /**
1092     * Gets the minimum of three {@code byte} values.
1093     *
1094     * @param a  value 1
1095     * @param b  value 2
1096     * @param c  value 3
1097     * @return  the smallest of the values
1098     */
1099    public static byte min(byte a, final byte b, final byte c) {
1100        if (b < a) {
1101            a = b;
1102        }
1103        if (c < a) {
1104            a = c;
1105        }
1106        return a;
1107    }
1108
1109    /**
1110     * Returns the minimum value in an array.
1111     *
1112     * @param array  an array, must not be null or empty
1113     * @return the minimum value in the array
1114     * @throws NullPointerException if {@code array} is {@code null}
1115     * @throws IllegalArgumentException if {@code array} is empty
1116     * @see IEEE754rUtils#min(double[]) IEEE754rUtils for a version of this method that handles NaN differently
1117     * @since 3.4 Changed signature from min(double[]) to min(double...)
1118     */
1119    public static double min(final double... array) {
1120        // Validates input
1121        validateArray(array);
1122
1123        // Finds and returns min
1124        double min = array[0];
1125        for (int i = 1; i < array.length; i++) {
1126            if (Double.isNaN(array[i])) {
1127                return Double.NaN;
1128            }
1129            if (array[i] < min) {
1130                min = array[i];
1131            }
1132        }
1133
1134        return min;
1135    }
1136
1137    /**
1138     * Gets the minimum of three {@code double} values.
1139     *
1140     * <p>If any value is {@code NaN}, {@code NaN} is
1141     * returned. Infinity is handled.</p>
1142     *
1143     * @param a  value 1
1144     * @param b  value 2
1145     * @param c  value 3
1146     * @return  the smallest of the values
1147     * @see IEEE754rUtils#min(double, double, double) for a version of this method that handles NaN differently
1148     */
1149    public static double min(final double a, final double b, final double c) {
1150        return Math.min(Math.min(a, b), c);
1151    }
1152
1153    /**
1154     * Returns the minimum value in an array.
1155     *
1156     * @param array  an array, must not be null or empty
1157     * @return the minimum value in the array
1158     * @throws NullPointerException if {@code array} is {@code null}
1159     * @throws IllegalArgumentException if {@code array} is empty
1160     * @see IEEE754rUtils#min(float[]) IEEE754rUtils for a version of this method that handles NaN differently
1161     * @since 3.4 Changed signature from min(float[]) to min(float...)
1162     */
1163    public static float min(final float... array) {
1164        // Validates input
1165        validateArray(array);
1166
1167        // Finds and returns min
1168        float min = array[0];
1169        for (int i = 1; i < array.length; i++) {
1170            if (Float.isNaN(array[i])) {
1171                return Float.NaN;
1172            }
1173            if (array[i] < min) {
1174                min = array[i];
1175            }
1176        }
1177
1178        return min;
1179    }
1180
1181    /**
1182     * Gets the minimum of three {@code float} values.
1183     *
1184     * <p>If any value is {@code NaN}, {@code NaN} is
1185     * returned. Infinity is handled.</p>
1186     *
1187     * @param a  value 1
1188     * @param b  value 2
1189     * @param c  value 3
1190     * @return  the smallest of the values
1191     * @see IEEE754rUtils#min(float, float, float) for a version of this method that handles NaN differently
1192     */
1193    public static float min(final float a, final float b, final float c) {
1194        return Math.min(Math.min(a, b), c);
1195    }
1196
1197    /**
1198     * Returns the minimum value in an array.
1199     *
1200     * @param array  an array, must not be null or empty
1201     * @return the minimum value in the array
1202     * @throws NullPointerException if {@code array} is {@code null}
1203     * @throws IllegalArgumentException if {@code array} is empty
1204     * @since 3.4 Changed signature from min(int[]) to min(int...)
1205     */
1206    public static int min(final int... array) {
1207        // Validates input
1208        validateArray(array);
1209
1210        // Finds and returns min
1211        int min = array[0];
1212        for (int j = 1; j < array.length; j++) {
1213            if (array[j] < min) {
1214                min = array[j];
1215            }
1216        }
1217
1218        return min;
1219    }
1220
1221     /**
1222     * Gets the minimum of three {@code int} values.
1223     *
1224     * @param a  value 1
1225     * @param b  value 2
1226     * @param c  value 3
1227     * @return  the smallest of the values
1228     */
1229    public static int min(int a, final int b, final int c) {
1230        if (b < a) {
1231            a = b;
1232        }
1233        if (c < a) {
1234            a = c;
1235        }
1236        return a;
1237    }
1238
1239    /**
1240     * Returns the minimum value in an array.
1241     *
1242     * @param array  an array, must not be null or empty
1243     * @return the minimum value in the array
1244     * @throws NullPointerException if {@code array} is {@code null}
1245     * @throws IllegalArgumentException if {@code array} is empty
1246     * @since 3.4 Changed signature from min(long[]) to min(long...)
1247     */
1248    public static long min(final long... array) {
1249        // Validates input
1250        validateArray(array);
1251
1252        // Finds and returns min
1253        long min = array[0];
1254        for (int i = 1; i < array.length; i++) {
1255            if (array[i] < min) {
1256                min = array[i];
1257            }
1258        }
1259
1260        return min;
1261    }
1262
1263    // 3 param min
1264    /**
1265     * Gets the minimum of three {@code long} values.
1266     *
1267     * @param a  value 1
1268     * @param b  value 2
1269     * @param c  value 3
1270     * @return  the smallest of the values
1271     */
1272    public static long min(long a, final long b, final long c) {
1273        if (b < a) {
1274            a = b;
1275        }
1276        if (c < a) {
1277            a = c;
1278        }
1279        return a;
1280    }
1281
1282    /**
1283     * Returns the minimum value in an array.
1284     *
1285     * @param array  an array, must not be null or empty
1286     * @return the minimum value in the array
1287     * @throws NullPointerException if {@code array} is {@code null}
1288     * @throws IllegalArgumentException if {@code array} is empty
1289     * @since 3.4 Changed signature from min(short[]) to min(short...)
1290     */
1291    public static short min(final short... array) {
1292        // Validates input
1293        validateArray(array);
1294
1295        // Finds and returns min
1296        short min = array[0];
1297        for (int i = 1; i < array.length; i++) {
1298            if (array[i] < min) {
1299                min = array[i];
1300            }
1301        }
1302
1303        return min;
1304    }
1305
1306    /**
1307     * Gets the minimum of three {@code short} values.
1308     *
1309     * @param a  value 1
1310     * @param b  value 2
1311     * @param c  value 3
1312     * @return  the smallest of the values
1313     */
1314    public static short min(short a, final short b, final short c) {
1315        if (b < a) {
1316            a = b;
1317        }
1318        if (c < a) {
1319            a = c;
1320        }
1321        return a;
1322    }
1323
1324    /**
1325     * Convert a {@link String} to a {@code byte}, returning
1326     * {@code zero} if the conversion fails.
1327     *
1328     * <p>If the string is {@code null}, {@code zero} is returned.</p>
1329     *
1330     * <pre>
1331     *   NumberUtils.toByte(null) = 0
1332     *   NumberUtils.toByte("")   = 0
1333     *   NumberUtils.toByte("1")  = 1
1334     * </pre>
1335     *
1336     * @param str  the string to convert, may be null
1337     * @return the byte represented by the string, or {@code zero} if
1338     *  conversion fails
1339     * @since 2.5
1340     */
1341    public static byte toByte(final String str) {
1342        return toByte(str, (byte) 0);
1343    }
1344
1345    /**
1346     * Convert a {@link String} to a {@code byte}, returning a
1347     * default value if the conversion fails.
1348     *
1349     * <p>If the string is {@code null}, the default value is returned.</p>
1350     *
1351     * <pre>
1352     *   NumberUtils.toByte(null, 1) = 1
1353     *   NumberUtils.toByte("", 1)   = 1
1354     *   NumberUtils.toByte("1", 0)  = 1
1355     * </pre>
1356     *
1357     * @param str  the string to convert, may be null
1358     * @param defaultValue  the default value
1359     * @return the byte represented by the string, or the default if conversion fails
1360     * @since 2.5
1361     */
1362    public static byte toByte(final String str, final byte defaultValue) {
1363        if (str == null) {
1364            return defaultValue;
1365        }
1366        try {
1367            return Byte.parseByte(str);
1368        } catch (final NumberFormatException nfe) {
1369            return defaultValue;
1370        }
1371    }
1372
1373    /**
1374     * Convert a {@link BigDecimal} to a {@code double}.
1375     *
1376     * <p>If the {@link BigDecimal} {@code value} is
1377     * {@code null}, then the specified default value is returned.</p>
1378     *
1379     * <pre>
1380     *   NumberUtils.toDouble(null)                     = 0.0d
1381     *   NumberUtils.toDouble(BigDecimal.valueOf(8.5d)) = 8.5d
1382     * </pre>
1383     *
1384     * @param value the {@link BigDecimal} to convert, may be {@code null}.
1385     * @return the double represented by the {@link BigDecimal} or
1386     *  {@code 0.0d} if the {@link BigDecimal} is {@code null}.
1387     * @since 3.8
1388     */
1389    public static double toDouble(final BigDecimal value) {
1390        return toDouble(value, 0.0d);
1391    }
1392
1393    /**
1394     * Convert a {@link BigDecimal} to a {@code double}.
1395     *
1396     * <p>If the {@link BigDecimal} {@code value} is
1397     * {@code null}, then the specified default value is returned.</p>
1398     *
1399     * <pre>
1400     *   NumberUtils.toDouble(null, 1.1d)                     = 1.1d
1401     *   NumberUtils.toDouble(BigDecimal.valueOf(8.5d), 1.1d) = 8.5d
1402     * </pre>
1403     *
1404     * @param value the {@link BigDecimal} to convert, may be {@code null}.
1405     * @param defaultValue the default value
1406     * @return the double represented by the {@link BigDecimal} or the
1407     *  defaultValue if the {@link BigDecimal} is {@code null}.
1408     * @since 3.8
1409     */
1410    public static double toDouble(final BigDecimal value, final double defaultValue) {
1411        return value == null ? defaultValue : value.doubleValue();
1412    }
1413
1414    /**
1415     * Convert a {@link String} to a {@code double}, returning
1416     * {@code 0.0d} if the conversion fails.
1417     *
1418     * <p>If the string {@code str} is {@code null},
1419     * {@code 0.0d} is returned.</p>
1420     *
1421     * <pre>
1422     *   NumberUtils.toDouble(null)   = 0.0d
1423     *   NumberUtils.toDouble("")     = 0.0d
1424     *   NumberUtils.toDouble("1.5")  = 1.5d
1425     * </pre>
1426     *
1427     * @param str the string to convert, may be {@code null}
1428     * @return the double represented by the string, or {@code 0.0d}
1429     *  if conversion fails
1430     * @since 2.1
1431     */
1432    public static double toDouble(final String str) {
1433        return toDouble(str, 0.0d);
1434    }
1435
1436    /**
1437     * Convert a {@link String} to a {@code double}, returning a
1438     * default value if the conversion fails.
1439     *
1440     * <p>If the string {@code str} is {@code null}, the default
1441     * value is returned.</p>
1442     *
1443     * <pre>
1444     *   NumberUtils.toDouble(null, 1.1d)   = 1.1d
1445     *   NumberUtils.toDouble("", 1.1d)     = 1.1d
1446     *   NumberUtils.toDouble("1.5", 0.0d)  = 1.5d
1447     * </pre>
1448     *
1449     * @param str the string to convert, may be {@code null}
1450     * @param defaultValue the default value
1451     * @return the double represented by the string, or defaultValue
1452     *  if conversion fails
1453     * @since 2.1
1454     */
1455    public static double toDouble(final String str, final double defaultValue) {
1456      if (str == null) {
1457          return defaultValue;
1458      }
1459      try {
1460          return Double.parseDouble(str);
1461      } catch (final NumberFormatException nfe) {
1462          return defaultValue;
1463      }
1464    }
1465
1466    /**
1467     * Convert a {@link String} to a {@code float}, returning
1468     * {@code 0.0f} if the conversion fails.
1469     *
1470     * <p>If the string {@code str} is {@code null},
1471     * {@code 0.0f} is returned.</p>
1472     *
1473     * <pre>
1474     *   NumberUtils.toFloat(null)   = 0.0f
1475     *   NumberUtils.toFloat("")     = 0.0f
1476     *   NumberUtils.toFloat("1.5")  = 1.5f
1477     * </pre>
1478     *
1479     * @param str the string to convert, may be {@code null}
1480     * @return the float represented by the string, or {@code 0.0f}
1481     *  if conversion fails
1482     * @since 2.1
1483     */
1484    public static float toFloat(final String str) {
1485        return toFloat(str, 0.0f);
1486    }
1487
1488    /**
1489     * Convert a {@link String} to a {@code float}, returning a
1490     * default value if the conversion fails.
1491     *
1492     * <p>If the string {@code str} is {@code null}, the default
1493     * value is returned.</p>
1494     *
1495     * <pre>
1496     *   NumberUtils.toFloat(null, 1.1f)   = 1.1f
1497     *   NumberUtils.toFloat("", 1.1f)     = 1.1f
1498     *   NumberUtils.toFloat("1.5", 0.0f)  = 1.5f
1499     * </pre>
1500     *
1501     * @param str the string to convert, may be {@code null}
1502     * @param defaultValue the default value
1503     * @return the float represented by the string, or defaultValue
1504     *  if conversion fails
1505     * @since 2.1
1506     */
1507    public static float toFloat(final String str, final float defaultValue) {
1508      if (str == null) {
1509          return defaultValue;
1510      }
1511      try {
1512          return Float.parseFloat(str);
1513      } catch (final NumberFormatException nfe) {
1514          return defaultValue;
1515      }
1516    }
1517
1518    /**
1519     * Convert a {@link String} to an {@code int}, returning
1520     * {@code zero} if the conversion fails.
1521     *
1522     * <p>If the string is {@code null}, {@code zero} is returned.</p>
1523     *
1524     * <pre>
1525     *   NumberUtils.toInt(null) = 0
1526     *   NumberUtils.toInt("")   = 0
1527     *   NumberUtils.toInt("1")  = 1
1528     * </pre>
1529     *
1530     * @param str  the string to convert, may be null
1531     * @return the int represented by the string, or {@code zero} if
1532     *  conversion fails
1533     * @since 2.1
1534     */
1535    public static int toInt(final String str) {
1536        return toInt(str, 0);
1537    }
1538
1539    /**
1540     * Convert a {@link String} to an {@code int}, returning a
1541     * default value if the conversion fails.
1542     *
1543     * <p>If the string is {@code null}, the default value is returned.</p>
1544     *
1545     * <pre>
1546     *   NumberUtils.toInt(null, 1) = 1
1547     *   NumberUtils.toInt("", 1)   = 1
1548     *   NumberUtils.toInt("1", 0)  = 1
1549     * </pre>
1550     *
1551     * @param str  the string to convert, may be null
1552     * @param defaultValue  the default value
1553     * @return the int represented by the string, or the default if conversion fails
1554     * @since 2.1
1555     */
1556    public static int toInt(final String str, final int defaultValue) {
1557        if (str == null) {
1558            return defaultValue;
1559        }
1560        try {
1561            return Integer.parseInt(str);
1562        } catch (final NumberFormatException nfe) {
1563            return defaultValue;
1564        }
1565    }
1566
1567    /**
1568     * Convert a {@link String} to a {@code long}, returning
1569     * {@code zero} if the conversion fails.
1570     *
1571     * <p>If the string is {@code null}, {@code zero} is returned.</p>
1572     *
1573     * <pre>
1574     *   NumberUtils.toLong(null) = 0L
1575     *   NumberUtils.toLong("")   = 0L
1576     *   NumberUtils.toLong("1")  = 1L
1577     * </pre>
1578     *
1579     * @param str  the string to convert, may be null
1580     * @return the long represented by the string, or {@code 0} if
1581     *  conversion fails
1582     * @since 2.1
1583     */
1584    public static long toLong(final String str) {
1585        return toLong(str, 0L);
1586    }
1587
1588    /**
1589     * Convert a {@link String} to a {@code long}, returning a
1590     * default value if the conversion fails.
1591     *
1592     * <p>If the string is {@code null}, the default value is returned.</p>
1593     *
1594     * <pre>
1595     *   NumberUtils.toLong(null, 1L) = 1L
1596     *   NumberUtils.toLong("", 1L)   = 1L
1597     *   NumberUtils.toLong("1", 0L)  = 1L
1598     * </pre>
1599     *
1600     * @param str  the string to convert, may be null
1601     * @param defaultValue  the default value
1602     * @return the long represented by the string, or the default if conversion fails
1603     * @since 2.1
1604     */
1605    public static long toLong(final String str, final long defaultValue) {
1606        if (str == null) {
1607            return defaultValue;
1608        }
1609        try {
1610            return Long.parseLong(str);
1611        } catch (final NumberFormatException nfe) {
1612            return defaultValue;
1613        }
1614    }
1615
1616    /**
1617     * Convert a {@link BigDecimal} to a {@link BigDecimal} with a scale of
1618     * two that has been rounded using {@code RoundingMode.HALF_EVEN}. If the supplied
1619     * {@code value} is null, then {@code BigDecimal.ZERO} is returned.
1620     *
1621     * <p>Note, the scale of a {@link BigDecimal} is the number of digits to the right of the
1622     * decimal point.</p>
1623     *
1624     * @param value the {@link BigDecimal} to convert, may be null.
1625     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
1626     * @since 3.8
1627     */
1628    public static BigDecimal toScaledBigDecimal(final BigDecimal value) {
1629        return toScaledBigDecimal(value, INTEGER_TWO, RoundingMode.HALF_EVEN);
1630    }
1631
1632    /**
1633     * Convert a {@link BigDecimal} to a {@link BigDecimal} whose scale is the
1634     * specified value with a {@link RoundingMode} applied. If the input {@code value}
1635     * is {@code null}, we simply return {@code BigDecimal.ZERO}.
1636     *
1637     * @param value the {@link BigDecimal} to convert, may be null.
1638     * @param scale the number of digits to the right of the decimal point.
1639     * @param roundingMode a rounding behavior for numerical operations capable of
1640     *  discarding precision.
1641     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
1642     * @since 3.8
1643     */
1644    public static BigDecimal toScaledBigDecimal(final BigDecimal value, final int scale, final RoundingMode roundingMode) {
1645        if (value == null) {
1646            return BigDecimal.ZERO;
1647        }
1648        return value.setScale(
1649            scale,
1650            roundingMode == null ? RoundingMode.HALF_EVEN : roundingMode
1651        );
1652    }
1653
1654    /**
1655     * Convert a {@link Double} to a {@link BigDecimal} with a scale of
1656     * two that has been rounded using {@code RoundingMode.HALF_EVEN}. If the supplied
1657     * {@code value} is null, then {@code BigDecimal.ZERO} is returned.
1658     *
1659     * <p>Note, the scale of a {@link BigDecimal} is the number of digits to the right of the
1660     * decimal point.</p>
1661     *
1662     * @param value the {@link Double} to convert, may be null.
1663     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
1664     * @since 3.8
1665     */
1666    public static BigDecimal toScaledBigDecimal(final Double value) {
1667        return toScaledBigDecimal(value, INTEGER_TWO, RoundingMode.HALF_EVEN);
1668    }
1669
1670    /**
1671     * Convert a {@link Double} to a {@link BigDecimal} whose scale is the
1672     * specified value with a {@link RoundingMode} applied. If the input {@code value}
1673     * is {@code null}, we simply return {@code BigDecimal.ZERO}.
1674     *
1675     * @param value the {@link Double} to convert, may be null.
1676     * @param scale the number of digits to the right of the decimal point.
1677     * @param roundingMode a rounding behavior for numerical operations capable of
1678     *  discarding precision.
1679     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
1680     * @since 3.8
1681     */
1682    public static BigDecimal toScaledBigDecimal(final Double value, final int scale, final RoundingMode roundingMode) {
1683        if (value == null) {
1684            return BigDecimal.ZERO;
1685        }
1686        return toScaledBigDecimal(
1687            BigDecimal.valueOf(value),
1688            scale,
1689            roundingMode
1690        );
1691    }
1692
1693    /**
1694     * Convert a {@link Float} to a {@link BigDecimal} with a scale of
1695     * two that has been rounded using {@code RoundingMode.HALF_EVEN}. If the supplied
1696     * {@code value} is null, then {@code BigDecimal.ZERO} is returned.
1697     *
1698     * <p>Note, the scale of a {@link BigDecimal} is the number of digits to the right of the
1699     * decimal point.</p>
1700     *
1701     * @param value the {@link Float} to convert, may be null.
1702     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
1703     * @since 3.8
1704     */
1705    public static BigDecimal toScaledBigDecimal(final Float value) {
1706        return toScaledBigDecimal(value, INTEGER_TWO, RoundingMode.HALF_EVEN);
1707    }
1708
1709    /**
1710     * Convert a {@link Float} to a {@link BigDecimal} whose scale is the
1711     * specified value with a {@link RoundingMode} applied. If the input {@code value}
1712     * is {@code null}, we simply return {@code BigDecimal.ZERO}.
1713     *
1714     * @param value the {@link Float} to convert, may be null.
1715     * @param scale the number of digits to the right of the decimal point.
1716     * @param roundingMode a rounding behavior for numerical operations capable of
1717     *  discarding precision.
1718     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
1719     * @since 3.8
1720     */
1721    public static BigDecimal toScaledBigDecimal(final Float value, final int scale, final RoundingMode roundingMode) {
1722        if (value == null) {
1723            return BigDecimal.ZERO;
1724        }
1725        return toScaledBigDecimal(
1726            BigDecimal.valueOf(value),
1727            scale,
1728            roundingMode
1729        );
1730    }
1731
1732    /**
1733     * Convert a {@link String} to a {@link BigDecimal} with a scale of
1734     * two that has been rounded using {@code RoundingMode.HALF_EVEN}. If the supplied
1735     * {@code value} is null, then {@code BigDecimal.ZERO} is returned.
1736     *
1737     * <p>Note, the scale of a {@link BigDecimal} is the number of digits to the right of the
1738     * decimal point.</p>
1739     *
1740     * @param value the {@link String} to convert, may be null.
1741     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
1742     * @since 3.8
1743     */
1744    public static BigDecimal toScaledBigDecimal(final String value) {
1745        return toScaledBigDecimal(value, INTEGER_TWO, RoundingMode.HALF_EVEN);
1746    }
1747
1748    /**
1749     * Convert a {@link String} to a {@link BigDecimal} whose scale is the
1750     * specified value with a {@link RoundingMode} applied. If the input {@code value}
1751     * is {@code null}, we simply return {@code BigDecimal.ZERO}.
1752     *
1753     * @param value the {@link String} to convert, may be null.
1754     * @param scale the number of digits to the right of the decimal point.
1755     * @param roundingMode a rounding behavior for numerical operations capable of
1756     *  discarding precision.
1757     * @return the scaled, with appropriate rounding, {@link BigDecimal}.
1758     * @since 3.8
1759     */
1760    public static BigDecimal toScaledBigDecimal(final String value, final int scale, final RoundingMode roundingMode) {
1761        if (value == null) {
1762            return BigDecimal.ZERO;
1763        }
1764        return toScaledBigDecimal(
1765            createBigDecimal(value),
1766            scale,
1767            roundingMode
1768        );
1769    }
1770
1771    /**
1772     * Convert a {@link String} to a {@code short}, returning
1773     * {@code zero} if the conversion fails.
1774     *
1775     * <p>If the string is {@code null}, {@code zero} is returned.</p>
1776     *
1777     * <pre>
1778     *   NumberUtils.toShort(null) = 0
1779     *   NumberUtils.toShort("")   = 0
1780     *   NumberUtils.toShort("1")  = 1
1781     * </pre>
1782     *
1783     * @param str  the string to convert, may be null
1784     * @return the short represented by the string, or {@code zero} if
1785     *  conversion fails
1786     * @since 2.5
1787     */
1788    public static short toShort(final String str) {
1789        return toShort(str, (short) 0);
1790    }
1791
1792    /**
1793     * Convert a {@link String} to an {@code short}, returning a
1794     * default value if the conversion fails.
1795     *
1796     * <p>If the string is {@code null}, the default value is returned.</p>
1797     *
1798     * <pre>
1799     *   NumberUtils.toShort(null, 1) = 1
1800     *   NumberUtils.toShort("", 1)   = 1
1801     *   NumberUtils.toShort("1", 0)  = 1
1802     * </pre>
1803     *
1804     * @param str  the string to convert, may be null
1805     * @param defaultValue  the default value
1806     * @return the short represented by the string, or the default if conversion fails
1807     * @since 2.5
1808     */
1809    public static short toShort(final String str, final short defaultValue) {
1810        if (str == null) {
1811            return defaultValue;
1812        }
1813        try {
1814            return Short.parseShort(str);
1815        } catch (final NumberFormatException nfe) {
1816            return defaultValue;
1817        }
1818    }
1819
1820    /**
1821     * Checks if the specified array is neither null nor empty.
1822     *
1823     * @param array  the array to check
1824     * @throws IllegalArgumentException if {@code array} is empty
1825     * @throws NullPointerException if {@code array} is {@code null}
1826     */
1827    private static void validateArray(final Object array) {
1828        Objects.requireNonNull(array, "array");
1829        Validate.isTrue(Array.getLength(array) != 0, "Array cannot be empty.");
1830    }
1831
1832    private static boolean withDecimalsParsing(final String str, final int beginIdx) {
1833        int decimalPoints = 0;
1834        for (int i = beginIdx; i < str.length(); i++) {
1835            final char ch = str.charAt(i);
1836            final boolean isDecimalPoint = ch == '.';
1837            if (isDecimalPoint) {
1838                decimalPoints++;
1839            }
1840            if (decimalPoints > 1) {
1841                return false;
1842            }
1843            if (!isDecimalPoint && !Character.isDigit(ch)) {
1844                return false;
1845            }
1846        }
1847        return true;
1848    }
1849
1850    /**
1851     * {@link NumberUtils} instances should NOT be constructed in standard programming.
1852     * Instead, the class should be used as {@code NumberUtils.toInt("6");}.
1853     *
1854     * <p>This constructor is public to permit tools that require a JavaBean instance
1855     * to operate.</p>
1856     *
1857     * @deprecated TODO Make private in 4.0.
1858     */
1859    @Deprecated
1860    public NumberUtils() {
1861        // empty
1862    }
1863}