Added compare methods for double and float
Added min/max methods for long Added public constructor with comment git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/lang/trunk@137023 13f79535-47bb-0310-9956-ffa450edef68
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Stephen Colebourne
parent
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@ -57,15 +57,27 @@
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import java.math.BigInteger;
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import java.math.BigDecimal;
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/**
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* Provides extra functionality for java Number classes.
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* Provides extra functionality for Java Number classes.
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*
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* @author <a href="mailto:bayard@generationjava.com">Henri Yandell</a>
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* @author <a href="mailto:rand_mcneely@yahoo.com">Rand McNeely</a>
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* @author <a href="mailto:scolebourne@joda.org">Stephen Colebourne</a>
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* @version $Id: NumberUtils.java,v 1.1 2002/07/19 03:35:54 bayard Exp $
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* @author <a href="mailto:steve.downey@netfolio.com">Steve Downey</a>
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* @version $Id: NumberUtils.java,v 1.2 2002/09/15 10:26:42 scolebourne Exp $
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*/
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public final class NumberUtils {
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/**
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* NumberUtils instances should NOT be constructed in standard programming.
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* Instead, the class should be used as <code>NumberUtils.stringToInt("6");</code>.
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* This constructor is public to permit tools that require a JavaBean instance
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* to operate.
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*/
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public NumberUtils() {
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}
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//--------------------------------------------------------------------
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/**
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* Convert a String to an int, returning zero if the conversion fails
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*
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@ -92,6 +104,8 @@ public static int stringToInt(String str, int defaultValue) {
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}
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}
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//--------------------------------------------------------------------
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// must handle Long, Float, Integer, Float, Short,
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// BigDecimal, BigInteger and Byte
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// useful methods:
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@ -312,6 +326,8 @@ private static boolean isAllZeros(String s) {
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return s.length() > 0;
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}
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//--------------------------------------------------------------------
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/**
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* Convert a String to a Float
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*
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@ -382,8 +398,33 @@ public static BigDecimal createBigDecimal(String val) {
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return bd;
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}
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//--------------------------------------------------------------------
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/**
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* Get the minimum of three values.
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* Gets the minimum of three long values.
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*
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* @param a value 1
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* @param b value 2
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* @param c value 3
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* @return the largest of the values
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*/
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public static long minimum(long a, long b, long c) {
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if (b < a) {
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a = b;
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}
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if (c < a) {
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a = c;
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}
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return a;
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}
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/**
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* Gets the minimum of three int values.
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*
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* @param a value 1
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* @param b value 2
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* @param c value 3
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* @return the largest of the values
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*/
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public static int minimum(int a, int b, int c) {
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if (b < a) {
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@ -396,7 +437,30 @@ public static int minimum(int a, int b, int c) {
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}
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/**
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* Get the maximum of three values.
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* Gets the maximum of three long values.
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*
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* @param a value 1
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* @param b value 2
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* @param c value 3
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* @return the largest of the values
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*/
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public static long maximum(long a, long b, long c) {
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if (b > a) {
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a = b;
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}
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if (c > a) {
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a = c;
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}
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return a;
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}
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/**
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* Gets the maximum of three int values.
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*
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* @param a value 1
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* @param b value 2
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* @param c value 3
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* @return the largest of the values
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*/
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public static int maximum(int a, int b, int c) {
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if (b > a) {
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@ -408,6 +472,122 @@ public static int maximum(int a, int b, int c) {
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return a;
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}
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//--------------------------------------------------------------------
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/**
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* Compares two doubles for order.
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* <p>
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* This method is more comprhensive than the standard Java greater than,
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* less than and equals operators.
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* It returns -1 if the first value is less than the second.
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* It returns +1 if the first value is greater than the second.
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* It returns 0 if the values are equal.
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* <p>
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* The ordering is as follows, largest to smallest:
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* <ul>
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* <li>NaN
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* <li>Positive infinity
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* <li>Maximum double
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* <li>Normal positve numbers
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* <li>+0.0
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* <li>-0.0
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* <li>Minimum double (-Double.MAX_VALUE)
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* <li>Normal negative numbers
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* <li>Negative infinity
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* </ul>
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* Comparing NaN with NaN will return 0.
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*
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* @param lhs the first double
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* @param rhs the second double
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* @return -1 if lhs is less, +1 if greater, 0 if equal to rhs
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*/
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public static int compare(double lhs, double rhs) {
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if (lhs < rhs) {
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return -1;
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}
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if (lhs > rhs) {
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return +1;
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}
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// Need to compare bits to handle 0.0 == -0.0 being true
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// compare should put -0.0 < +0.0
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// Two NaNs are also == for compare purposes
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// where NaN == NaN is false
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long lhsBits = Double.doubleToLongBits(lhs);
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long rhsBits = Double.doubleToLongBits(rhs);
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if (lhsBits == rhsBits) {
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return 0;
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}
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// Something exotic! A comparison to NaN or 0.0 vs -0.0
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// Fortunately NaN's long is > than everything else
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// Also negzeros bits < poszero
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// NAN: 9221120237041090560
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// MAX: 9218868437227405311
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// NEGZERO: -9223372036854775808
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if (lhsBits < rhsBits) {
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return -1;
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} else {
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return +1;
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}
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}
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/**
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* Compares two floats for order.
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* <p>
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* This method is more comprhensive than the standard Java greater than,
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* less than and equals operators.
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* It returns -1 if the first value is less than the second.
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* It returns +1 if the first value is greater than the second.
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* It returns 0 if the values are equal.
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* <p>
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* The ordering is as follows, largest to smallest:
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* <ul>
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* <li>NaN
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* <li>Positive infinity
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* <li>Maximum float
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* <li>Normal positve numbers
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* <li>+0.0
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* <li>-0.0
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* <li>Normal negative numbers
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* <li>Minimum float (-Float.MAX_VALUE)
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* <li>Negative infinity
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* </ul>
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* Comparing NaN with NaN will return 0.
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*
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* @param lhs the first float
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* @param rhs the second float
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* @return -1 if lhs is less, +1 if greater, 0 if equal to rhs
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*/
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public static int compare(float lhs, float rhs) {
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if (lhs < rhs) {
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return -1;
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}
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if (lhs > rhs) {
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return +1;
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}
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//Need to compare bits to handle 0.0 == -0.0 being true
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// compare should put -0.0 < +0.0
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// Two NaNs are also == for compare purposes
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// where NaN == NaN is false
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int lhsBits = Float.floatToIntBits(lhs);
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int rhsBits = Float.floatToIntBits(rhs);
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if (lhsBits == rhsBits) {
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return 0;
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}
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//Something exotic! A comparison to NaN or 0.0 vs -0.0
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//Fortunately NaN's int is > than everything else
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//Also negzeros bits < poszero
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//NAN: 2143289344
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//MAX: 2139095039
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//NEGZERO: -2147483648
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if (lhsBits < rhsBits) {
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return -1;
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} else {
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return +1;
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}
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}
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//--------------------------------------------------------------------
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/**
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* Checks whether the String contains only digit characters.
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* Null and blank string will return false.
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