Java如何获取数字的符号函数？
下面的代码向您展示如何使用Math.signum()静态方法调用获取数字的符号函数。此方法提取实数的符号。如果你有许多x的符号函数x是-1如果x<0;0如果x=0和1如果x>0。
package org.nhooo.example.math;
public class SignumExample {
public static void main(String[] args) {
Double zero = 0.0D;
Double negative = -25.0D;
Double positive = 15.0D;
//获取数字值的符号函数。
//它返回：
//*0（如果值为零）。
//*1.0（如果值大于零）。
//*-1.0，如果值小于零。
double sign1 = Math.signum(zero);
double sign2 = Math.signum(negative);
double sign3 = Math.signum(positive);
//对于浮点值
float sign4 = Math.signum(zero.floatValue());
float sign5 = Math.signum(negative.floatValue());
float sign6 = Math.signum(positive.floatValue());
System.out.println("In double:");
System.out.println("Signum of " + zero + " is " + sign1);
System.out.println("Signum of " + negative + " is " + sign2);
System.out.println("Signum of " + positive + " is " + sign3);
System.out.println("In float:");
System.out.println("Signum of " + zero + " is " + sign4);
System.out.println("Signum of " + negative + " is " + sign5);
System.out.println("Signum of " + positive + " is " + sign6);
}
}这是程序的输出：
In double: Signum of 0.0 is 0.0 Signum of -25.0 is -1.0 Signum of 15.0 is 1.0 In float: Signum of 0.0 is 0.0 Signum of -25.0 is -1.0 Signum of 15.0 is 1.0