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