/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.lang3.math;

import java.lang.reflect.Array;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.math.RoundingMode;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.Validate;

/**
 * <p>
 * Provides extra functionality for Java Number classes.
 * </p>
 *
 * @since 2.0
 */
public class NumberUtils {

	/** Reusable Long constant for zero. */
	public static final Long LONG_ZERO = Long.valueOf(0L);
	/** Reusable Long constant for one. */
	public static final Long LONG_ONE = Long.valueOf(1L);
	/** Reusable Long constant for minus one. */
	public static final Long LONG_MINUS_ONE = Long.valueOf(-1L);
	/** Reusable Integer constant for zero. */
	public static final Integer INTEGER_ZERO = Integer.valueOf(0);
	/** Reusable Integer constant for one. */
	public static final Integer INTEGER_ONE = Integer.valueOf(1);
	/** Reusable Integer constant for two */
	public static final Integer INTEGER_TWO = Integer.valueOf(2);
	/** Reusable Integer constant for minus one. */
	public static final Integer INTEGER_MINUS_ONE = Integer.valueOf(-1);
	/** Reusable Short constant for zero. */
	public static final Short SHORT_ZERO = Short.valueOf((short) 0);
	/** Reusable Short constant for one. */
	public static final Short SHORT_ONE = Short.valueOf((short) 1);
	/** Reusable Short constant for minus one. */
	public static final Short SHORT_MINUS_ONE = Short.valueOf((short) -1);
	/** Reusable Byte constant for zero. */
	public static final Byte BYTE_ZERO = Byte.valueOf((byte) 0);
	/** Reusable Byte constant for one. */
	public static final Byte BYTE_ONE = Byte.valueOf((byte) 1);
	/** Reusable Byte constant for minus one. */
	public static final Byte BYTE_MINUS_ONE = Byte.valueOf((byte) -1);
	/** Reusable Double constant for zero. */
	public static final Double DOUBLE_ZERO = Double.valueOf(0.0d);
	/** Reusable Double constant for one. */
	public static final Double DOUBLE_ONE = Double.valueOf(1.0d);
	/** Reusable Double constant for minus one. */
	public static final Double DOUBLE_MINUS_ONE = Double.valueOf(-1.0d);
	/** Reusable Float constant for zero. */
	public static final Float FLOAT_ZERO = Float.valueOf(0.0f);
	/** Reusable Float constant for one. */
	public static final Float FLOAT_ONE = Float.valueOf(1.0f);
	/** Reusable Float constant for minus one. */
	public static final Float FLOAT_MINUS_ONE = Float.valueOf(-1.0f);

	/**
	 * {@link Integer#MAX_VALUE} as a {@link Long}.
	 *
	 * @since 3.12.0
	 */
	public static final Long LONG_INT_MAX_VALUE = Long.valueOf(Integer.MAX_VALUE);

	/**
	 * {@link Integer#MIN_VALUE} as a {@link Long}.
	 *
	 * @since 3.12.0
	 */
	public static final Long LONG_INT_MIN_VALUE = Long.valueOf(Integer.MIN_VALUE);

	/**
	 * <p>
	 * Compares two {@code byte} values numerically. This is the same functionality
	 * as provided in Java 7.
	 * </p>
	 *
	 * @param x the first {@code byte} to compare
	 * @param y the second {@code byte} to compare
	 * @return the value {@code 0} if {@code x == y}; a value less than {@code 0} if
	 *         {@code x < y}; and a value greater than {@code 0} if {@code x > y}
	 * @since 3.4
	 */
	public static int compare(final byte x, final byte y) {
		return x - y;
	}

	/**
	 * <p>
	 * Compares two {@code int} values numerically. This is the same functionality
	 * as provided in Java 7.
	 * </p>
	 *
	 * @param x the first {@code int} to compare
	 * @param y the second {@code int} to compare
	 * @return the value {@code 0} if {@code x == y}; a value less than {@code 0} if
	 *         {@code x < y}; and a value greater than {@code 0} if {@code x > y}
	 * @since 3.4
	 */
	public static int compare(final int x, final int y) {
		if (x == y) {
			return 0;
		}
		return x < y ? -1 : 1;
	}

	/**
	 * <p>
	 * Compares to {@code long} values numerically. This is the same functionality
	 * as provided in Java 7.
	 * </p>
	 *
	 * @param x the first {@code long} to compare
	 * @param y the second {@code long} to compare
	 * @return the value {@code 0} if {@code x == y}; a value less than {@code 0} if
	 *         {@code x < y}; and a value greater than {@code 0} if {@code x > y}
	 * @since 3.4
	 */
	public static int compare(final long x, final long y) {
		if (x == y) {
			return 0;
		}
		return x < y ? -1 : 1;
	}

	/**
	 * <p>
	 * Compares to {@code short} values numerically. This is the same functionality
	 * as provided in Java 7.
	 * </p>
	 *
	 * @param x the first {@code short} to compare
	 * @param y the second {@code short} to compare
	 * @return the value {@code 0} if {@code x == y}; a value less than {@code 0} if
	 *         {@code x < y}; and a value greater than {@code 0} if {@code x > y}
	 * @since 3.4
	 */
	public static int compare(final short x, final short y) {
		if (x == y) {
			return 0;
		}
		return x < y ? -1 : 1;
	}

	/**
	 * <p>
	 * Convert a {@code String} to a {@code BigDecimal}.
	 * </p>
	 *
	 * <p>
	 * Returns {@code null} if the string is {@code null}.
	 * </p>
	 *
	 * @param str a {@code String} to convert, may be null
	 * @return converted {@code BigDecimal} (or null if the input is null)
	 * @throws NumberFormatException if the value cannot be converted
	 */
	public static BigDecimal createBigDecimal(final String str) {
		if (str == null) {
			return null;
		}
		// handle JDK1.3.1 bug where "" throws IndexOutOfBoundsException
		if (StringUtils.isBlank(str)) {
			throw new NumberFormatException("A blank string is not a valid number");
		}
		return new BigDecimal(str);
	}

	/**
	 * <p>
	 * Convert a {@code String} to a {@code BigInteger}; since 3.2 it handles hex
	 * (0x or #) and octal (0) notations.
	 * </p>
	 *
	 * <p>
	 * Returns {@code null} if the string is {@code null}.
	 * </p>
	 *
	 * @param str a {@code String} to convert, may be null
	 * @return converted {@code BigInteger} (or null if the input is null)
	 * @throws NumberFormatException if the value cannot be converted
	 */
	public static BigInteger createBigInteger(final String str) {
		if (str == null) {
			return null;
		}
		int pos = 0; // offset within string
		int radix = 10;
		boolean negate = false; // need to negate later?
		if (str.startsWith("-")) {
			negate = true;
			pos = 1;
		}
		if (str.startsWith("0x", pos) || str.startsWith("0X", pos)) { // hex
			radix = 16;
			pos += 2;
		} else if (str.startsWith("#", pos)) { // alternative hex (allowed by Long/Integer)
			radix = 16;
			pos++;
		} else if (str.startsWith("0", pos) && str.length() > pos + 1) { // octal; so long as there are additional
																			// digits
			radix = 8;
			pos++;
		} // default is to treat as decimal

		final BigInteger value = new BigInteger(str.substring(pos), radix);
		return negate ? value.negate() : value;
	}

	/**
	 * <p>
	 * Convert a {@code String} to a {@code Double}.
	 * </p>
	 *
	 * <p>
	 * Returns {@code null} if the string is {@code null}.
	 * </p>
	 *
	 * @param str a {@code String} to convert, may be null
	 * @return converted {@code Double} (or null if the input is null)
	 * @throws NumberFormatException if the value cannot be converted
	 */
	public static Double createDouble(final String str) {
		if (str == null) {
			return null;
		}
		return Double.valueOf(str);
	}

	// -----------------------------------------------------------------------
	/**
	 * <p>
	 * Convert a {@code String} to a {@code Float}.
	 * </p>
	 *
	 * <p>
	 * Returns {@code null} if the string is {@code null}.
	 * </p>
	 *
	 * @param str a {@code String} to convert, may be null
	 * @return converted {@code Float} (or null if the input is null)
	 * @throws NumberFormatException if the value cannot be converted
	 */
	public static Float createFloat(final String str) {
		if (str == null) {
			return null;
		}
		return Float.valueOf(str);
	}

	/**
	 * <p>
	 * Convert a {@code String} to a {@code Integer}, handling hex (0xhhhh) and
	 * octal (0dddd) notations. N.B. a leading zero means octal; spaces are not
	 * trimmed.
	 * </p>
	 *
	 * <p>
	 * Returns {@code null} if the string is {@code null}.
	 * </p>
	 *
	 * @param str a {@code String} to convert, may be null
	 * @return converted {@code Integer} (or null if the input is null)
	 * @throws NumberFormatException if the value cannot be converted
	 */
	public static Integer createInteger(final String str) {
		if (str == null) {
			return null;
		}
		// decode() handles 0xAABD and 0777 (hex and octal) as well.
		return Integer.decode(str);
	}

	/**
	 * <p>
	 * Convert a {@code String} to a {@code Long}; since 3.1 it handles hex (0Xhhhh)
	 * and octal (0ddd) notations. N.B. a leading zero means octal; spaces are not
	 * trimmed.
	 * </p>
	 *
	 * <p>
	 * Returns {@code null} if the string is {@code null}.
	 * </p>
	 *
	 * @param str a {@code String} to convert, may be null
	 * @return converted {@code Long} (or null if the input is null)
	 * @throws NumberFormatException if the value cannot be converted
	 */
	public static Long createLong(final String str) {
		if (str == null) {
			return null;
		}
		return Long.decode(str);
	}

	/**
	 * <p>
	 * Turns a string value into a java.lang.Number.
	 * </p>
	 *
	 * <p>
	 * If the string starts with {@code 0x} or {@code -0x} (lower or upper case) or
	 * {@code #} or {@code -#}, it will be interpreted as a hexadecimal Integer - or
	 * Long, if the number of digits after the prefix is more than 8 - or BigInteger
	 * if there are more than 16 digits.
	 * </p>
	 * <p>
	 * Then, the value is examined for a type qualifier on the end, i.e. one of
	 * {@code 'f', 'F', 'd', 'D', 'l', 'L'}. If it is found, it starts trying to
	 * create successively larger types from the type specified until one is found
	 * that can represent the value.
	 * </p>
	 *
	 * <p>
	 * If a type specifier is not found, it will check for a decimal point and then
	 * try successively larger types from {@code Integer} to {@code BigInteger} and
	 * from {@code Float} to {@code BigDecimal}.
	 * </p>
	 *
	 * <p>
	 * Integral values with a leading {@code 0} will be interpreted as octal; the
	 * returned number will be Integer, Long or BigDecimal as appropriate.
	 * </p>
	 *
	 * <p>
	 * Returns {@code null} if the string is {@code null}.
	 * </p>
	 *
	 * <p>
	 * This method does not trim the input string, i.e., strings with leading or
	 * trailing spaces will generate NumberFormatExceptions.
	 * </p>
	 *
	 * @param str String containing a number, may be null
	 * @return Number created from the string (or null if the input is null)
	 * @throws NumberFormatException if the value cannot be converted
	 */
	public static Number createNumber(final String str) {
		if (str == null) {
			return null;
		}
		if (StringUtils.isBlank(str)) {
			throw new NumberFormatException("A blank string is not a valid number");
		}
		// Need to deal with all possible hex prefixes here
		final String[] hex_prefixes = { "0x", "0X", "-0x", "-0X", "#", "-#" };
		final int length = str.length();
		int pfxLen = 0;
		for (final String pfx : hex_prefixes) {
			if (str.startsWith(pfx)) {
				pfxLen += pfx.length();
				break;
			}
		}
		if (pfxLen > 0) { // we have a hex number
			char firstSigDigit = 0; // strip leading zeroes
			for (int i = pfxLen; i < length; i++) {
				firstSigDigit = str.charAt(i);
				if (firstSigDigit == '0') { // count leading zeroes
					pfxLen++;
				} else {
					break;
				}
			}
			final int hexDigits = length - pfxLen;
			if (hexDigits > 16 || hexDigits == 16 && firstSigDigit > '7') { // too many for Long
				return createBigInteger(str);
			}
			if (hexDigits > 8 || hexDigits == 8 && firstSigDigit > '7') { // too many for an int
				return createLong(str);
			}
			return createInteger(str);
		}
		final char lastChar = str.charAt(length - 1);
		final String mant;
		final String dec;
		final String exp;
		final int decPos = str.indexOf('.');
		final int expPos = str.indexOf('e') + str.indexOf('E') + 1; // assumes both not present
		// if both e and E are present, this is caught by the checks on expPos (which
		// prevent IOOBE)
		// and the parsing which will detect if e or E appear in a number due to using
		// the wrong offset

		if (decPos > -1) { // there is a decimal point
			if (expPos > -1) { // there is an exponent
				if (expPos < decPos || expPos > length) { // prevents double exponent causing IOOBE
					throw new NumberFormatException(str + " is not a valid number.");
				}
				dec = str.substring(decPos + 1, expPos);
			} else {
				dec = str.substring(decPos + 1);
			}
			mant = getMantissa(str, decPos);
		} else {
			if (expPos > -1) {
				if (expPos > length) { // prevents double exponent causing IOOBE
					throw new NumberFormatException(str + " is not a valid number.");
				}
				mant = getMantissa(str, expPos);
			} else {
				mant = getMantissa(str);
			}
			dec = null;
		}
		if (!Character.isDigit(lastChar) && lastChar != '.') {
			if (expPos > -1 && expPos < length - 1) {
				exp = str.substring(expPos + 1, length - 1);
			} else {
				exp = null;
			}
			// Requesting a specific type..
			final String numeric = str.substring(0, length - 1);
			final boolean allZeros = isAllZeros(mant) && isAllZeros(exp);
			switch (lastChar) {
			case 'l':
			case 'L':
				if (dec == null && exp == null
						&& (!numeric.isEmpty() && numeric.charAt(0) == '-' && isDigits(numeric.substring(1))
								|| isDigits(numeric))) {
					try {
						return createLong(numeric);
					} catch (final NumberFormatException nfe) { // NOPMD
						// Too big for a long
					}
					return createBigInteger(numeric);

				}
				throw new NumberFormatException(str + " is not a valid number.");
			case 'f':
			case 'F':
				try {
					final Float f = createFloat(str);
					if (!(f.isInfinite() || f.floatValue() == 0.0F && !allZeros)) {
						// If it's too big for a float or the float value = 0 and the string
						// has non-zeros in it, then float does not have the precision we want
						return f;
					}

				} catch (final NumberFormatException nfe) { // NOPMD
					// ignore the bad number
				}
				//$FALL-THROUGH$
			case 'd':
			case 'D':
				try {
					final Double d = createDouble(str);
					if (!(d.isInfinite() || d.doubleValue() == 0.0D && !allZeros)) {
						return d;
					}
				} catch (final NumberFormatException nfe) { // NOPMD
					// ignore the bad number
				}
				try {
					return createBigDecimal(numeric);
				} catch (final NumberFormatException e) { // NOPMD
					// ignore the bad number
				}
				//$FALL-THROUGH$
			default:
				throw new NumberFormatException(str + " is not a valid number.");

			}
		}
		// User doesn't have a preference on the return type, so let's start
		// small and go from there...
		if (expPos > -1 && expPos < length - 1) {
			exp = str.substring(expPos + 1);
		} else {
			exp = null;
		}
		if (dec == null && exp == null) { // no decimal point and no exponent
			// Must be an Integer, Long, Biginteger
			try {
				return createInteger(str);
			} catch (final NumberFormatException nfe) { // NOPMD
				// ignore the bad number
			}
			try {
				return createLong(str);
			} catch (final NumberFormatException nfe) { // NOPMD
				// ignore the bad number
			}
			return createBigInteger(str);
		}

		// Must be a Float, Double, BigDecimal
		final boolean allZeros = isAllZeros(mant) && isAllZeros(exp);
		try {
			final Float f = createFloat(str);
			final Double d = createDouble(str);
			if (!f.isInfinite() && !(f.floatValue() == 0.0F && !allZeros) && f.toString().equals(d.toString())) {
				return f;
			}
			if (!d.isInfinite() && !(d.doubleValue() == 0.0D && !allZeros)) {
				final BigDecimal b = createBigDecimal(str);
				if (b.compareTo(BigDecimal.valueOf(d.doubleValue())) == 0) {
					return d;
				}
				return b;
			}
		} catch (final NumberFormatException nfe) { // NOPMD
			// ignore the bad number
		}
		return createBigDecimal(str);
	}

	/**
	 * <p>
	 * Utility method for {@link #createNumber(java.lang.String)}.
	 * </p>
	 *
	 * <p>
	 * Returns mantissa of the given number.
	 * </p>
	 *
	 * @param str the string representation of the number
	 * @return mantissa of the given number
	 */
	private static String getMantissa(final String str) {
		return getMantissa(str, str.length());
	}

	/**
	 * <p>
	 * Utility method for {@link #createNumber(java.lang.String)}.
	 * </p>
	 *
	 * <p>
	 * Returns mantissa of the given number.
	 * </p>
	 *
	 * @param str     the string representation of the number
	 * @param stopPos the position of the exponent or decimal point
	 * @return mantissa of the given number
	 */
	private static String getMantissa(final String str, final int stopPos) {
		final char firstChar = str.charAt(0);
		final boolean hasSign = firstChar == '-' || firstChar == '+';

		return hasSign ? str.substring(1, stopPos) : str.substring(0, stopPos);
	}

	/**
	 * <p>
	 * Utility method for {@link #createNumber(java.lang.String)}.
	 * </p>
	 *
	 * <p>
	 * Returns {@code true} if s is {@code null}.
	 * </p>
	 *
	 * @param str the String to check
	 * @return if it is all zeros or {@code null}
	 */
	private static boolean isAllZeros(final String str) {
		if (str == null) {
			return true;
		}
		for (int i = str.length() - 1; i >= 0; i--) {
			if (str.charAt(i) != '0') {
				return false;
			}
		}
		return !str.isEmpty();
	}

	/**
	 * <p>
	 * Checks whether the String a valid Java number.
	 * </p>
	 *
	 * <p>
	 * Valid numbers include hexadecimal marked with the {@code 0x} or {@code 0X}
	 * qualifier, octal numbers, scientific notation and numbers marked with a type
	 * qualifier (e.g. 123L).
	 * </p>
	 *
	 * <p>
	 * Non-hexadecimal strings beginning with a leading zero are treated as octal
	 * values. Thus the string {@code 09} will return {@code false}, since {@code 9}
	 * is not a valid octal value. However, numbers beginning with {@code 0.} are
	 * treated as decimal.
	 * </p>
	 *
	 * <p>
	 * {@code null} and empty/blank {@code String} will return {@code false}.
	 * </p>
	 *
	 * <p>
	 * Note, {@link #createNumber(String)} should return a number for every input
	 * resulting in {@code true}.
	 * </p>
	 *
	 * @param str the {@code String} to check
	 * @return {@code true} if the string is a correctly formatted number
	 * @since 3.5
	 */
	public static boolean isCreatable(final String str) {
		if (StringUtils.isEmpty(str)) {
			return false;
		}
		final char[] chars = str.toCharArray();
		int sz = chars.length;
		boolean hasExp = false;
		boolean hasDecPoint = false;
		boolean allowSigns = false;
		boolean foundDigit = false;
		// deal with any possible sign up front
		final int start = chars[0] == '-' || chars[0] == '+' ? 1 : 0;
		if (sz > start + 1 && chars[start] == '0' && !StringUtils.contains(str, '.')) { // leading 0, skip if is a
																						// decimal number
			if (chars[start + 1] == 'x' || chars[start + 1] == 'X') { // leading 0x/0X
				int i = start + 2;
				if (i == sz) {
					return false; // str == "0x"
				}
				// checking hex (it can't be anything else)
				for (; i < chars.length; i++) {
					if ((chars[i] < '0' || chars[i] > '9') && (chars[i] < 'a' || chars[i] > 'f')
							&& (chars[i] < 'A' || chars[i] > 'F')) {
						return false;
					}
				}
				return true;
			} else if (Character.isDigit(chars[start + 1])) {
				// leading 0, but not hex, must be octal
				int i = start + 1;
				for (; i < chars.length; i++) {
					if (chars[i] < '0' || chars[i] > '7') {
						return false;
					}
				}
				return true;
			}
		}
		sz--; // don't want to loop to the last char, check it afterwords
				// for type qualifiers
		int i = start;
		// loop to the next to last char or to the last char if we need another digit to
		// make a valid number (e.g. chars[0..5] = "1234E")
		while (i < sz || i < sz + 1 && allowSigns && !foundDigit) {
			if (chars[i] >= '0' && chars[i] <= '9') {
				foundDigit = true;
				allowSigns = false;

			} else if (chars[i] == '.') {
				if (hasDecPoint || hasExp) {
					// two decimal points or dec in exponent
					return false;
				}
				hasDecPoint = true;
			} else if (chars[i] == 'e' || chars[i] == 'E') {
				// we've already taken care of hex.
				if (hasExp) {
					// two E's
					return false;
				}
				if (!foundDigit) {
					return false;
				}
				hasExp = true;
				allowSigns = true;
			} else if (chars[i] == '+' || chars[i] == '-') {
				if (!allowSigns) {
					return false;
				}
				allowSigns = false;
				foundDigit = false; // we need a digit after the E
			} else {
				return false;
			}
			i++;
		}
		if (i < chars.length) {
			if (chars[i] >= '0' && chars[i] <= '9') {
				// no type qualifier, OK
				return true;
			}
			if (chars[i] == 'e' || chars[i] == 'E') {
				// can't have an E at the last byte
				return false;
			}
			if (chars[i] == '.') {
				if (hasDecPoint || hasExp) {
					// two decimal points or dec in exponent
					return false;
				}
				// single trailing decimal point after non-exponent is ok
				return foundDigit;
			}
			if (!allowSigns && (chars[i] == 'd' || chars[i] == 'D' || chars[i] == 'f' || chars[i] == 'F')) {
				return foundDigit;
			}
			if (chars[i] == 'l' || chars[i] == 'L') {
				// not allowing L with an exponent or decimal point
				return foundDigit && !hasExp && !hasDecPoint;
			}
			// last character is illegal
			return false;
		}
		// allowSigns is true iff the val ends in 'E'
		// found digit it to make sure weird stuff like '.' and '1E-' doesn't pass
		return !allowSigns && foundDigit;
	}

	// -----------------------------------------------------------------------
	/**
	 * <p>
	 * Checks whether the {@code String} contains only digit characters.
	 * </p>
	 *
	 * <p>
	 * {@code Null} and empty String will return {@code false}.
	 * </p>
	 *
	 * @param str the {@code String} to check
	 * @return {@code true} if str contains only Unicode numeric
	 */
	public static boolean isDigits(final String str) {
		return StringUtils.isNumeric(str);
	}

	/**
	 * <p>
	 * Checks whether the String a valid Java number.
	 * </p>
	 *
	 * <p>
	 * Valid numbers include hexadecimal marked with the {@code 0x} or {@code 0X}
	 * qualifier, octal numbers, scientific notation and numbers marked with a type
	 * qualifier (e.g. 123L).
	 * </p>
	 *
	 * <p>
	 * Non-hexadecimal strings beginning with a leading zero are treated as octal
	 * values. Thus the string {@code 09} will return {@code false}, since {@code 9}
	 * is not a valid octal value. However, numbers beginning with {@code 0.} are
	 * treated as decimal.
	 * </p>
	 *
	 * <p>
	 * {@code null} and empty/blank {@code String} will return {@code false}.
	 * </p>
	 *
	 * <p>
	 * Note, {@link #createNumber(String)} should return a number for every input
	 * resulting in {@code true}.
	 * </p>
	 *
	 * @param str the {@code String} to check
	 * @return {@code true} if the string is a correctly formatted number
	 * @since 3.3 the code supports hex {@code 0Xhhh} an octal {@code 0ddd}
	 *        validation
	 * @deprecated This feature will be removed in Lang 4.0, use
	 *             {@link NumberUtils#isCreatable(String)} instead
	 */
	@Deprecated
	public static boolean isNumber(final String str) {
		return isCreatable(str);
	}

	/**
	 * <p>
	 * Checks whether the given String is a parsable number.
	 * </p>
	 *
	 * <p>
	 * Parsable numbers include those Strings understood by
	 * {@link Integer#parseInt(String)}, {@link Long#parseLong(String)},
	 * {@link Float#parseFloat(String)} or {@link Double#parseDouble(String)}. This
	 * method can be used instead of catching {@link java.text.ParseException} when
	 * calling one of those methods.
	 * </p>
	 *
	 * <p>
	 * Hexadecimal and scientific notations are <strong>not</strong> considered
	 * parsable. See {@link #isCreatable(String)} on those cases.
	 * </p>
	 *
	 * <p>
	 * {@code Null} and empty String will return {@code false}.
	 * </p>
	 *
	 * @param str the String to check.
	 * @return {@code true} if the string is a parsable number.
	 * @since 3.4
	 */
	public static boolean isParsable(final String str) {
		if (StringUtils.isEmpty(str)) {
			return false;
		}
		if (str.charAt(str.length() - 1) == '.') {
			return false;
		}
		if (str.charAt(0) == '-') {
			if (str.length() == 1) {
				return false;
			}
			return withDecimalsParsing(str, 1);
		}
		return withDecimalsParsing(str, 0);
	}

	/**
	 * <p>
	 * Returns the maximum value in an array.
	 * </p>
	 *
	 * @param array an array, must not be null or empty
	 * @return the maximum value in the array
	 * @throws IllegalArgumentException if {@code array} is {@code null}
	 * @throws IllegalArgumentException if {@code array} is empty
	 * @since 3.4 Changed signature from max(byte[]) to max(byte...)
	 */
	public static byte max(final byte... array) {
		// Validates input
		validateArray(array);

		// Finds and returns max
		byte max = array[0];
		for (int i = 1; i < array.length; i++) {
			if (array[i] > max) {
				max = array[i];
			}
		}

		return max;
	}

	/**
	 * <p>
	 * Gets the maximum of three {@code byte} values.
	 * </p>
	 *
	 * @param a value 1
	 * @param b value 2
	 * @param c value 3
	 * @return the largest of the values
	 */
	public static byte max(byte a, final byte b, final byte c) {
		if (b > a) {
			a = b;
		}
		if (c > a) {
			a = c;
		}
		return a;
	}

	/**
	 * <p>
	 * Returns the maximum value in an array.
	 * </p>
	 *
	 * @param array an array, must not be null or empty
	 * @return the maximum value in the array
	 * @throws IllegalArgumentException if {@code array} is {@code null}
	 * @throws IllegalArgumentException if {@code array} is empty
	 * @see IEEE754rUtils#max(double[]) IEEE754rUtils for a version of this method
	 *      that handles NaN differently
	 * @since 3.4 Changed signature from max(double[]) to max(double...)
	 */
	public static double max(final double... array) {
		// Validates input
		validateArray(array);

		// Finds and returns max
		double max = array[0];
		for (int j = 1; j < array.length; j++) {
			if (Double.isNaN(array[j])) {
				return Double.NaN;
			}
			if (array[j] > max) {
				max = array[j];
			}
		}

		return max;
	}

	/**
	 * <p>
	 * Gets the maximum of three {@code double} values.
	 * </p>
	 *
	 * <p>
	 * If any value is {@code NaN}, {@code NaN} is returned. Infinity is handled.
	 * </p>
	 *
	 * @param a value 1
	 * @param b value 2
	 * @param c value 3
	 * @return the largest of the values
	 * @see IEEE754rUtils#max(double, double, double) for a version of this method
	 *      that handles NaN differently
	 */
	public static double max(final double a, final double b, final double c) {
		return Math.max(Math.max(a, b), c);
	}

	/**
	 * <p>
	 * Returns the maximum value in an array.
	 * </p>
	 *
	 * @param array an array, must not be null or empty
	 * @return the maximum value in the array
	 * @throws IllegalArgumentException if {@code array} is {@code null}
	 * @throws IllegalArgumentException if {@code array} is empty
	 * @see IEEE754rUtils#max(float[]) IEEE754rUtils for a version of this method
	 *      that handles NaN differently
	 * @since 3.4 Changed signature from max(float[]) to max(float...)
	 */
	public static float max(final float... array) {
		// Validates input
		validateArray(array);

		// Finds and returns max
		float max = array[0];
		for (int j = 1; j < array.length; j++) {
			if (Float.isNaN(array[j])) {
				return Float.NaN;
			}
			if (array[j] > max) {
				max = array[j];
			}
		}

		return max;
	}

	// -----------------------------------------------------------------------
	// must handle Long, Float, Integer, Float, Short,
	// BigDecimal, BigInteger and Byte
	// useful methods:
	// Byte.decode(String)
	// Byte.valueOf(String, int radix)
	// Byte.valueOf(String)
	// Double.valueOf(String)
	// Float.valueOf(String)
	// Float.valueOf(String)
	// Integer.valueOf(String, int radix)
	// Integer.valueOf(String)
	// Integer.decode(String)
	// Integer.getInteger(String)
	// Integer.getInteger(String, int val)
	// Integer.getInteger(String, Integer val)
	// Integer.valueOf(String)
	// Double.valueOf(String)
	// new Byte(String)
	// Long.valueOf(String)
	// Long.getLong(String)
	// Long.getLong(String, int)
	// Long.getLong(String, Integer)
	// Long.valueOf(String, int)
	// Long.valueOf(String)
	// Short.valueOf(String)
	// Short.decode(String)
	// Short.valueOf(String, int)
	// Short.valueOf(String)
	// new BigDecimal(String)
	// new BigInteger(String)
	// new BigInteger(String, int radix)
	// Possible inputs:
	// 45 45.5 45E7 4.5E7 Hex Oct Binary xxxF xxxD xxxf xxxd
	// plus minus everything. Prolly more. A lot are not separable.

	/**
	 * <p>
	 * Gets the maximum of three {@code float} values.
	 * </p>
	 *
	 * <p>
	 * If any value is {@code NaN}, {@code NaN} is returned. Infinity is handled.
	 * </p>
	 *
	 * @param a value 1
	 * @param b value 2
	 * @param c value 3
	 * @return the largest of the values
	 * @see IEEE754rUtils#max(float, float, float) for a version of this method that
	 *      handles NaN differently
	 */
	public static float max(final float a, final float b, final float c) {
		return Math.max(Math.max(a, b), c);
	}

	/**
	 * <p>
	 * Returns the maximum value in an array.
	 * </p>
	 *
	 * @param array an array, must not be null or empty
	 * @return the maximum value in the array
	 * @throws IllegalArgumentException if {@code array} is {@code null}
	 * @throws IllegalArgumentException if {@code array} is empty
	 * @since 3.4 Changed signature from max(int[]) to max(int...)
	 */
	public static int max(final int... array) {
		// Validates input
		validateArray(array);

		// Finds and returns max
		int max = array[0];
		for (int j = 1; j < array.length; j++) {
			if (array[j] > max) {
				max = array[j];
			}
		}

		return max;
	}

	/**
	 * <p>
	 * Gets the maximum of three {@code int} values.
	 * </p>
	 *
	 * @param a value 1
	 * @param b value 2
	 * @param c value 3
	 * @return the largest of the values
	 */
	public static int max(int a, final int b, final int c) {
		if (b > a) {
			a = b;
		}
		if (c > a) {
			a = c;
		}
		return a;
	}

	// Max in array
	// --------------------------------------------------------------------
	/**
	 * <p>
	 * Returns the maximum value in an array.
	 * </p>
	 *
	 * @param array an array, must not be null or empty
	 * @return the maximum value in the array
	 * @throws IllegalArgumentException if {@code array} is {@code null}
	 * @throws IllegalArgumentException if {@code array} is empty
	 * @since 3.4 Changed signature from max(long[]) to max(long...)
	 */
	public static long max(final long... array) {
		// Validates input
		validateArray(array);

		// Finds and returns max
		long max = array[0];
		for (int j = 1; j < array.length; j++) {
			if (array[j] > max) {
				max = array[j];
			}
		}

		return max;
	}

	// 3 param max
	// -----------------------------------------------------------------------
	/**
	 * <p>
	 * Gets the maximum of three {@code long} values.
	 * </p>
	 *
	 * @param a value 1
	 * @param b value 2
	 * @param c value 3
	 * @return the largest of the values
	 */
	public static long max(long a, final long b, final long c) {
		if (b > a) {
			a = b;
		}
		if (c > a) {
			a = c;
		}
		return a;
	}

	/**
	 * <p>
	 * Returns the maximum value in an array.
	 * </p>
	 *
	 * @param array an array, must not be null or empty
	 * @return the maximum value in the array
	 * @throws IllegalArgumentException if {@code array} is {@code null}
	 * @throws IllegalArgumentException if {@code array} is empty
	 * @since 3.4 Changed signature from max(short[]) to max(short...)
	 */
	public static short max(final short... array) {
		// Validates input
		validateArray(array);

		// Finds and returns max
		short max = array[0];
		for (int i = 1; i < array.length; i++) {
			if (array[i] > max) {
				max = array[i];
			}
		}

		return max;
	}

	/**
	 * <p>
	 * Gets the maximum of three {@code short} values.
	 * </p>
	 *
	 * @param a value 1
	 * @param b value 2
	 * @param c value 3
	 * @return the largest of the values
	 */
	public static short max(short a, final short b, final short c) {
		if (b > a) {
			a = b;
		}
		if (c > a) {
			a = c;
		}
		return a;
	}

	/**
	 * <p>
	 * Returns the minimum value in an array.
	 * </p>
	 *
	 * @param array an array, must not be null or empty
	 * @return the minimum value in the array
	 * @throws IllegalArgumentException if {@code array} is {@code null}
	 * @throws IllegalArgumentException if {@code array} is empty
	 * @since 3.4 Changed signature from min(byte[]) to min(byte...)
	 */
	public static byte min(final byte... array) {
		// Validates input
		validateArray(array);

		// Finds and returns min
		byte min = array[0];
		for (int i = 1; i < array.length; i++) {
			if (array[i] < min) {
				min = array[i];
			}
		}

		return min;
	}

	/**
	 * <p>
	 * Gets the minimum of three {@code byte} values.
	 * </p>
	 *
	 * @param a value 1
	 * @param b value 2
	 * @param c value 3
	 * @return the smallest of the values
	 */
	public static byte min(byte a, final byte b, final byte c) {
		if (b < a) {
			a = b;
		}
		if (c < a) {
			a = c;
		}
		return a;
	}

	/**
	 * <p>
	 * Returns the minimum value in an array.
	 * </p>
	 *
	 * @param array an array, must not be null or empty
	 * @return the minimum value in the array
	 * @throws IllegalArgumentException if {@code array} is {@code null}
	 * @throws IllegalArgumentException if {@code array} is empty
	 * @see IEEE754rUtils#min(double[]) IEEE754rUtils for a version of this method
	 *      that handles NaN differently
	 * @since 3.4 Changed signature from min(double[]) to min(double...)
	 */
	public static double min(final double... array) {
		// Validates input
		validateArray(array);

		// Finds and returns min
		double min = array[0];
		for (int i = 1; i < array.length; i++) {
			if (Double.isNaN(array[i])) {
				return Double.NaN;
			}
			if (array[i] < min) {
				min = array[i];
			}
		}

		return min;
	}

	/**
	 * <p>
	 * Gets the minimum of three {@code double} values.
	 * </p>
	 *
	 * <p>
	 * If any value is {@code NaN}, {@code NaN} is returned. Infinity is handled.
	 * </p>
	 *
	 * @param a value 1
	 * @param b value 2
	 * @param c value 3
	 * @return the smallest of the values
	 * @see IEEE754rUtils#min(double, double, double) for a version of this method
	 *      that handles NaN differently
	 */
	public static double min(final double a, final double b, final double c) {
		return Math.min(Math.min(a, b), c);
	}

	/**
	 * <p>
	 * Returns the minimum value in an array.
	 * </p>
	 *
	 * @param array an array, must not be null or empty
	 * @return the minimum value in the array
	 * @throws IllegalArgumentException if {@code array} is {@code null}
	 * @throws IllegalArgumentException if {@code array} is empty
	 * @see IEEE754rUtils#min(float[]) IEEE754rUtils for a version of this method
	 *      that handles NaN differently
	 * @since 3.4 Changed signature from min(float[]) to min(float...)
	 */
	public static float min(final float... array) {
		// Validates input
		validateArray(array);

		// Finds and returns min
		float min = array[0];
		for (int i = 1; i < array.length; i++) {
			if (Float.isNaN(array[i])) {
				return Float.NaN;
			}
			if (array[i] < min) {
				min = array[i];
			}
		}

		return min;
	}

	/**
	 * <p>
	 * Gets the minimum of three {@code float} values.
	 * </p>
	 *
	 * <p>
	 * If any value is {@code NaN}, {@code NaN} is returned. Infinity is handled.
	 * </p>
	 *
	 * @param a value 1
	 * @param b value 2
	 * @param c value 3
	 * @return the smallest of the values
	 * @see IEEE754rUtils#min(float, float, float) for a version of this method that
	 *      handles NaN differently
	 */
	public static float min(final float a, final float b, final float c) {
		return Math.min(Math.min(a, b), c);
	}

	/**
	 * <p>
	 * Returns the minimum value in an array.
	 * </p>
	 *
	 * @param array an array, must not be null or empty
	 * @return the minimum value in the array
	 * @throws IllegalArgumentException if {@code array} is {@code null}
	 * @throws IllegalArgumentException if {@code array} is empty
	 * @since 3.4 Changed signature from min(int[]) to min(int...)
	 */
	public static int min(final int... array) {
		// Validates input
		validateArray(array);

		// Finds and returns min
		int min = array[0];
		for (int j = 1; j < array.length; j++) {
			if (array[j] < min) {
				min = array[j];
			}
		}

		return min;
	}

	/**
	 * <p>
	 * Gets the minimum of three {@code int} values.
	 * </p>
	 *
	 * @param a value 1
	 * @param b value 2
	 * @param c value 3
	 * @return the smallest of the values
	 */
	public static int min(int a, final int b, final int c) {
		if (b < a) {
			a = b;
		}
		if (c < a) {
			a = c;
		}
		return a;
	}

	// Min in array
	// --------------------------------------------------------------------
	/**
	 * <p>
	 * Returns the minimum value in an array.
	 * </p>
	 *
	 * @param array an array, must not be null or empty
	 * @return the minimum value in the array
	 * @throws IllegalArgumentException if {@code array} is {@code null}
	 * @throws IllegalArgumentException if {@code array} is empty
	 * @since 3.4 Changed signature from min(long[]) to min(long...)
	 */
	public static long min(final long... array) {
		// Validates input
		validateArray(array);

		// Finds and returns min
		long min = array[0];
		for (int i = 1; i < array.length; i++) {
			if (array[i] < min) {
				min = array[i];
			}
		}

		return min;
	}

	// 3 param min
	// -----------------------------------------------------------------------
	/**
	 * <p>
	 * Gets the minimum of three {@code long} values.
	 * </p>
	 *
	 * @param a value 1
	 * @param b value 2
	 * @param c value 3
	 * @return the smallest of the values
	 */
	public static long min(long a, final long b, final long c) {
		if (b < a) {
			a = b;
		}
		if (c < a) {
			a = c;
		}
		return a;
	}

	/**
	 * <p>
	 * Returns the minimum value in an array.
	 * </p>
	 *
	 * @param array an array, must not be null or empty
	 * @return the minimum value in the array
	 * @throws IllegalArgumentException if {@code array} is {@code null}
	 * @throws IllegalArgumentException if {@code array} is empty
	 * @since 3.4 Changed signature from min(short[]) to min(short...)
	 */
	public static short min(final short... array) {
		// Validates input
		validateArray(array);

		// Finds and returns min
		short min = array[0];
		for (int i = 1; i < array.length; i++) {
			if (array[i] < min) {
				min = array[i];
			}
		}

		return min;
	}

	/**
	 * <p>
	 * Gets the minimum of three {@code short} values.
	 * </p>
	 *
	 * @param a value 1
	 * @param b value 2
	 * @param c value 3
	 * @return the smallest of the values
	 */
	public static short min(short a, final short b, final short c) {
		if (b < a) {
			a = b;
		}
		if (c < a) {
			a = c;
		}
		return a;
	}

	// -----------------------------------------------------------------------
	/**
	 * <p>
	 * Convert a {@code String} to a {@code byte}, returning {@code zero} if the
	 * conversion fails.
	 * </p>
	 *
	 * <p>
	 * If the string is {@code null}, {@code zero} is returned.
	 * </p>
	 *
	 * <pre>
	 *   NumberUtils.toByte(null) = 0
	 *   NumberUtils.toByte("")   = 0
	 *   NumberUtils.toByte("1")  = 1
	 * </pre>
	 *
	 * @param str the string to convert, may be null
	 * @return the byte represented by the string, or {@code zero} if conversion
	 *         fails
	 * @since 2.5
	 */
	public static byte toByte(final String str) {
		return toByte(str, (byte) 0);
	}

	/**
	 * <p>
	 * Convert a {@code String} to a {@code byte}, returning a default value if the
	 * conversion fails.
	 * </p>
	 *
	 * <p>
	 * If the string is {@code null}, the default value is returned.
	 * </p>
	 *
	 * <pre>
	 *   NumberUtils.toByte(null, 1) = 1
	 *   NumberUtils.toByte("", 1)   = 1
	 *   NumberUtils.toByte("1", 0)  = 1
	 * </pre>
	 *
	 * @param str          the string to convert, may be null
	 * @param defaultValue the default value
	 * @return the byte represented by the string, or the default if conversion
	 *         fails
	 * @since 2.5
	 */
	public static byte toByte(final String str, final byte defaultValue) {
		if (str == null) {
			return defaultValue;
		}
		try {
			return Byte.parseByte(str);
		} catch (final NumberFormatException nfe) {
			return defaultValue;
		}
	}

	/**
	 * <p>
	 * Convert a {@code BigDecimal} to a {@code double}.
	 * </p>
	 *
	 * <p>
	 * If the {@code BigDecimal} {@code value} is {@code null}, then the specified
	 * default value is returned.
	 * </p>
	 *
	 * <pre>
	 *   NumberUtils.toDouble(null)                     = 0.0d
	 *   NumberUtils.toDouble(BigDecimal.valudOf(8.5d)) = 8.5d
	 * </pre>
	 *
	 * @param value the {@code BigDecimal} to convert, may be {@code null}.
	 * @return the double represented by the {@code BigDecimal} or {@code 0.0d} if
	 *         the {@code BigDecimal} is {@code null}.
	 * @since 3.8
	 */
	public static double toDouble(final BigDecimal value) {
		return toDouble(value, 0.0d);
	}

	/**
	 * <p>
	 * Convert a {@code BigDecimal} to a {@code double}.
	 * </p>
	 *
	 * <p>
	 * If the {@code BigDecimal} {@code value} is {@code null}, then the specified
	 * default value is returned.
	 * </p>
	 *
	 * <pre>
	 *   NumberUtils.toDouble(null, 1.1d)                     = 1.1d
	 *   NumberUtils.toDouble(BigDecimal.valudOf(8.5d), 1.1d) = 8.5d
	 * </pre>
	 *
	 * @param value        the {@code BigDecimal} to convert, may be {@code null}.
	 * @param defaultValue the default value
	 * @return the double represented by the {@code BigDecimal} or the defaultValue
	 *         if the {@code BigDecimal} is {@code null}.
	 * @since 3.8
	 */
	public static double toDouble(final BigDecimal value, final double defaultValue) {
		return value == null ? defaultValue : value.doubleValue();
	}

	/**
	 * <p>
	 * Convert a {@code String} to a {@code double}, returning {@code 0.0d} if the
	 * conversion fails.
	 * </p>
	 *
	 * <p>
	 * If the string {@code str} is {@code null}, {@code 0.0d} is returned.
	 * </p>
	 *
	 * <pre>
	 *   NumberUtils.toDouble(null)   = 0.0d
	 *   NumberUtils.toDouble("")     = 0.0d
	 *   NumberUtils.toDouble("1.5")  = 1.5d
	 * </pre>
	 *
	 * @param str the string to convert, may be {@code null}
	 * @return the double represented by the string, or {@code 0.0d} if conversion
	 *         fails
	 * @since 2.1
	 */
	public static double toDouble(final String str) {
		return toDouble(str, 0.0d);
	}

	/**
	 * <p>
	 * Convert a {@code String} to a {@code double}, returning a default value if
	 * the conversion fails.
	 * </p>
	 *
	 * <p>
	 * If the string {@code str} is {@code null}, the default value is returned.
	 * </p>
	 *
	 * <pre>
	 *   NumberUtils.toDouble(null, 1.1d)   = 1.1d
	 *   NumberUtils.toDouble("", 1.1d)     = 1.1d
	 *   NumberUtils.toDouble("1.5", 0.0d)  = 1.5d
	 * </pre>
	 *
	 * @param str          the string to convert, may be {@code null}
	 * @param defaultValue the default value
	 * @return the double represented by the string, or defaultValue if conversion
	 *         fails
	 * @since 2.1
	 */
	public static double toDouble(final String str, final double defaultValue) {
		if (str == null) {
			return defaultValue;
		}
		try {
			return Double.parseDouble(str);
		} catch (final NumberFormatException nfe) {
			return defaultValue;
		}
	}

	/**
	 * <p>
	 * Convert a {@code String} to a {@code float}, returning {@code 0.0f} if the
	 * conversion fails.
	 * </p>
	 *
	 * <p>
	 * If the string {@code str} is {@code null}, {@code 0.0f} is returned.
	 * </p>
	 *
	 * <pre>
	 *   NumberUtils.toFloat(null)   = 0.0f
	 *   NumberUtils.toFloat("")     = 0.0f
	 *   NumberUtils.toFloat("1.5")  = 1.5f
	 * </pre>
	 *
	 * @param str the string to convert, may be {@code null}
	 * @return the float represented by the string, or {@code 0.0f} if conversion
	 *         fails
	 * @since 2.1
	 */
	public static float toFloat(final String str) {
		return toFloat(str, 0.0f);
	}

	/**
	 * <p>
	 * Convert a {@code String} to a {@code float}, returning a default value if the
	 * conversion fails.
	 * </p>
	 *
	 * <p>
	 * If the string {@code str} is {@code null}, the default value is returned.
	 * </p>
	 *
	 * <pre>
	 *   NumberUtils.toFloat(null, 1.1f)   = 1.0f
	 *   NumberUtils.toFloat("", 1.1f)     = 1.1f
	 *   NumberUtils.toFloat("1.5", 0.0f)  = 1.5f
	 * </pre>
	 *
	 * @param str          the string to convert, may be {@code null}
	 * @param defaultValue the default value
	 * @return the float represented by the string, or defaultValue if conversion
	 *         fails
	 * @since 2.1
	 */
	public static float toFloat(final String str, final float defaultValue) {
		if (str == null) {
			return defaultValue;
		}
		try {
			return Float.parseFloat(str);
		} catch (final NumberFormatException nfe) {
			return defaultValue;
		}
	}

	// -----------------------------------------------------------------------
	/**
	 * <p>
	 * Convert a {@code String} to an {@code int}, returning {@code zero} if the
	 * conversion fails.
	 * </p>
	 *
	 * <p>
	 * If the string is {@code null}, {@code zero} is returned.
	 * </p>
	 *
	 * <pre>
	 *   NumberUtils.toInt(null) = 0
	 *   NumberUtils.toInt("")   = 0
	 *   NumberUtils.toInt("1")  = 1
	 * </pre>
	 *
	 * @param str the string to convert, may be null
	 * @return the int represented by the string, or {@code zero} if conversion
	 *         fails
	 * @since 2.1
	 */
	public static int toInt(final String str) {
		return toInt(str, 0);
	}

	/**
	 * <p>
	 * Convert a {@code String} to an {@code int}, returning a default value if the
	 * conversion fails.
	 * </p>
	 *
	 * <p>
	 * If the string is {@code null}, the default value is returned.
	 * </p>
	 *
	 * <pre>
	 *   NumberUtils.toInt(null, 1) = 1
	 *   NumberUtils.toInt("", 1)   = 1
	 *   NumberUtils.toInt("1", 0)  = 1
	 * </pre>
	 *
	 * @param str          the string to convert, may be null
	 * @param defaultValue the default value
	 * @return the int represented by the string, or the default if conversion fails
	 * @since 2.1
	 */
	public static int toInt(final String str, final int defaultValue) {
		if (str == null) {
			return defaultValue;
		}
		try {
			return Integer.parseInt(str);
		} catch (final NumberFormatException nfe) {
			return defaultValue;
		}
	}

	/**
	 * <p>
	 * Convert a {@code String} to a {@code long}, returning {@code zero} if the
	 * conversion fails.
	 * </p>
	 *
	 * <p>
	 * If the string is {@code null}, {@code zero} is returned.
	 * </p>
	 *
	 * <pre>
	 *   NumberUtils.toLong(null) = 0L
	 *   NumberUtils.toLong("")   = 0L
	 *   NumberUtils.toLong("1")  = 1L
	 * </pre>
	 *
	 * @param str the string to convert, may be null
	 * @return the long represented by the string, or {@code 0} if conversion fails
	 * @since 2.1
	 */
	public static long toLong(final String str) {
		return toLong(str, 0L);
	}

	/**
	 * <p>
	 * Convert a {@code String} to a {@code long}, returning a default value if the
	 * conversion fails.
	 * </p>
	 *
	 * <p>
	 * If the string is {@code null}, the default value is returned.
	 * </p>
	 *
	 * <pre>
	 *   NumberUtils.toLong(null, 1L) = 1L
	 *   NumberUtils.toLong("", 1L)   = 1L
	 *   NumberUtils.toLong("1", 0L)  = 1L
	 * </pre>
	 *
	 * @param str          the string to convert, may be null
	 * @param defaultValue the default value
	 * @return the long represented by the string, or the default if conversion
	 *         fails
	 * @since 2.1
	 */
	public static long toLong(final String str, final long defaultValue) {
		if (str == null) {
			return defaultValue;
		}
		try {
			return Long.parseLong(str);
		} catch (final NumberFormatException nfe) {
			return defaultValue;
		}
	}

	/**
	 * Convert a {@code BigDecimal} to a {@code BigDecimal} with a scale of two that
	 * has been rounded using {@code RoundingMode.HALF_EVEN}. If the supplied
	 * {@code value} is null, then {@code BigDecimal.ZERO} is returned.
	 *
	 * <p>
	 * Note, the scale of a {@code BigDecimal} is the number of digits to the right
	 * of the decimal point.
	 * </p>
	 *
	 * @param value the {@code BigDecimal} to convert, may be null.
	 * @return the scaled, with appropriate rounding, {@code BigDecimal}.
	 * @since 3.8
	 */
	public static BigDecimal toScaledBigDecimal(final BigDecimal value) {
		return toScaledBigDecimal(value, INTEGER_TWO, RoundingMode.HALF_EVEN);
	}

	/**
	 * Convert a {@code BigDecimal} to a {@code BigDecimal} whose scale is the
	 * specified value with a {@code RoundingMode} applied. If the input
	 * {@code value} is {@code null}, we simply return {@code BigDecimal.ZERO}.
	 *
	 * @param value        the {@code BigDecimal} to convert, may be null.
	 * @param scale        the number of digits to the right of the decimal point.
	 * @param roundingMode a rounding behavior for numerical operations capable of
	 *                     discarding precision.
	 * @return the scaled, with appropriate rounding, {@code BigDecimal}.
	 * @since 3.8
	 */
	public static BigDecimal toScaledBigDecimal(final BigDecimal value, final int scale,
			final RoundingMode roundingMode) {
		if (value == null) {
			return BigDecimal.ZERO;
		}
		return value.setScale(scale, (roundingMode == null) ? RoundingMode.HALF_EVEN : roundingMode);
	}

	/**
	 * Convert a {@code Double} to a {@code BigDecimal} with a scale of two that has
	 * been rounded using {@code RoundingMode.HALF_EVEN}. If the supplied
	 * {@code value} is null, then {@code BigDecimal.ZERO} is returned.
	 *
	 * <p>
	 * Note, the scale of a {@code BigDecimal} is the number of digits to the right
	 * of the decimal point.
	 * </p>
	 *
	 * @param value the {@code Double} to convert, may be null.
	 * @return the scaled, with appropriate rounding, {@code BigDecimal}.
	 * @since 3.8
	 */
	public static BigDecimal toScaledBigDecimal(final Double value) {
		return toScaledBigDecimal(value, INTEGER_TWO, RoundingMode.HALF_EVEN);
	}

	/**
	 * Convert a {@code Double} to a {@code BigDecimal} whose scale is the specified
	 * value with a {@code RoundingMode} applied. If the input {@code value} is
	 * {@code null}, we simply return {@code BigDecimal.ZERO}.
	 *
	 * @param value        the {@code Double} to convert, may be null.
	 * @param scale        the number of digits to the right of the decimal point.
	 * @param roundingMode a rounding behavior for numerical operations capable of
	 *                     discarding precision.
	 * @return the scaled, with appropriate rounding, {@code BigDecimal}.
	 * @since 3.8
	 */
	public static BigDecimal toScaledBigDecimal(final Double value, final int scale, final RoundingMode roundingMode) {
		if (value == null) {
			return BigDecimal.ZERO;
		}
		return toScaledBigDecimal(BigDecimal.valueOf(value), scale, roundingMode);
	}

	/**
	 * Convert a {@code Float} to a {@code BigDecimal} with a scale of two that has
	 * been rounded using {@code RoundingMode.HALF_EVEN}. If the supplied
	 * {@code value} is null, then {@code BigDecimal.ZERO} is returned.
	 *
	 * <p>
	 * Note, the scale of a {@code BigDecimal} is the number of digits to the right
	 * of the decimal point.
	 * </p>
	 *
	 * @param value the {@code Float} to convert, may be null.
	 * @return the scaled, with appropriate rounding, {@code BigDecimal}.
	 * @since 3.8
	 */
	public static BigDecimal toScaledBigDecimal(final Float value) {
		return toScaledBigDecimal(value, INTEGER_TWO, RoundingMode.HALF_EVEN);
	}

	/**
	 * Convert a {@code Float} to a {@code BigDecimal} whose scale is the specified
	 * value with a {@code RoundingMode} applied. If the input {@code value} is
	 * {@code null}, we simply return {@code BigDecimal.ZERO}.
	 *
	 * @param value        the {@code Float} to convert, may be null.
	 * @param scale        the number of digits to the right of the decimal point.
	 * @param roundingMode a rounding behavior for numerical operations capable of
	 *                     discarding precision.
	 * @return the scaled, with appropriate rounding, {@code BigDecimal}.
	 * @since 3.8
	 */
	public static BigDecimal toScaledBigDecimal(final Float value, final int scale, final RoundingMode roundingMode) {
		if (value == null) {
			return BigDecimal.ZERO;
		}
		return toScaledBigDecimal(BigDecimal.valueOf(value), scale, roundingMode);
	}

	/**
	 * Convert a {@code String} to a {@code BigDecimal} with a scale of two that has
	 * been rounded using {@code RoundingMode.HALF_EVEN}. If the supplied
	 * {@code value} is null, then {@code BigDecimal.ZERO} is returned.
	 *
	 * <p>
	 * Note, the scale of a {@code BigDecimal} is the number of digits to the right
	 * of the decimal point.
	 * </p>
	 *
	 * @param value the {@code String} to convert, may be null.
	 * @return the scaled, with appropriate rounding, {@code BigDecimal}.
	 * @since 3.8
	 */
	public static BigDecimal toScaledBigDecimal(final String value) {
		return toScaledBigDecimal(value, INTEGER_TWO, RoundingMode.HALF_EVEN);
	}

	/**
	 * Convert a {@code String} to a {@code BigDecimal} whose scale is the specified
	 * value with a {@code RoundingMode} applied. If the input {@code value} is
	 * {@code null}, we simply return {@code BigDecimal.ZERO}.
	 *
	 * @param value        the {@code String} to convert, may be null.
	 * @param scale        the number of digits to the right of the decimal point.
	 * @param roundingMode a rounding behavior for numerical operations capable of
	 *                     discarding precision.
	 * @return the scaled, with appropriate rounding, {@code BigDecimal}.
	 * @since 3.8
	 */
	public static BigDecimal toScaledBigDecimal(final String value, final int scale, final RoundingMode roundingMode) {
		if (value == null) {
			return BigDecimal.ZERO;
		}
		return toScaledBigDecimal(createBigDecimal(value), scale, roundingMode);
	}

	/**
	 * <p>
	 * Convert a {@code String} to a {@code short}, returning {@code zero} if the
	 * conversion fails.
	 * </p>
	 *
	 * <p>
	 * If the string is {@code null}, {@code zero} is returned.
	 * </p>
	 *
	 * <pre>
	 *   NumberUtils.toShort(null) = 0
	 *   NumberUtils.toShort("")   = 0
	 *   NumberUtils.toShort("1")  = 1
	 * </pre>
	 *
	 * @param str the string to convert, may be null
	 * @return the short represented by the string, or {@code zero} if conversion
	 *         fails
	 * @since 2.5
	 */
	public static short toShort(final String str) {
		return toShort(str, (short) 0);
	}

	/**
	 * <p>
	 * Convert a {@code String} to an {@code short}, returning a default value if
	 * the conversion fails.
	 * </p>
	 *
	 * <p>
	 * If the string is {@code null}, the default value is returned.
	 * </p>
	 *
	 * <pre>
	 *   NumberUtils.toShort(null, 1) = 1
	 *   NumberUtils.toShort("", 1)   = 1
	 *   NumberUtils.toShort("1", 0)  = 1
	 * </pre>
	 *
	 * @param str          the string to convert, may be null
	 * @param defaultValue the default value
	 * @return the short represented by the string, or the default if conversion
	 *         fails
	 * @since 2.5
	 */
	public static short toShort(final String str, final short defaultValue) {
		if (str == null) {
			return defaultValue;
		}
		try {
			return Short.parseShort(str);
		} catch (final NumberFormatException nfe) {
			return defaultValue;
		}
	}

	/**
	 * Checks if the specified array is neither null nor empty.
	 *
	 * @param array the array to check
	 * @throws IllegalArgumentException if {@code array} is either {@code null} or
	 *                                  empty
	 */
	private static void validateArray(final Object array) {
		Validate.notNull(array, "array");
		Validate.isTrue(Array.getLength(array) != 0, "Array cannot be empty.");
	}

	private static boolean withDecimalsParsing(final String str, final int beginIdx) {
		int decimalPoints = 0;
		for (int i = beginIdx; i < str.length(); i++) {
			final boolean isDecimalPoint = str.charAt(i) == '.';
			if (isDecimalPoint) {
				decimalPoints++;
			}
			if (decimalPoints > 1) {
				return false;
			}
			if (!isDecimalPoint && !Character.isDigit(str.charAt(i))) {
				return false;
			}
		}
		return true;
	}

	/**
	 * <p>
	 * {@code NumberUtils} instances should NOT be constructed in standard
	 * programming. Instead, the class should be used as
	 * {@code NumberUtils.toInt("6");}.
	 * </p>
	 *
	 * <p>
	 * This constructor is public to permit tools that require a JavaBean instance
	 * to operate.
	 * </p>
	 */
	public NumberUtils() {
	}
}
