Java Integer signum()方法

signum函数是一个提取实数符号的奇数数学函数。signum函数也被称为符号函数。

java.lang的Integer.signum()方法返回指定整数值的符号函数。对于正值、负值和零，该方法分别返回1、-1和0。

语法:

public static int signum(int a)

参数： 该方法需要一个整数类型的参数 a ，要对其进行操作。

返回值： 该方法返回指定整数值的signum函数。如果指定的值是负的，则返回-1，如果指定的值是0，则返回0，如果指定的值是正的，则返回1。

例子

Consider an integer a = 27Since 27 is a positive int signum will return= 1Consider another integer a = -61Since -61 is a negative int signum will return= -1Consider the integer value _a_ = 0For a zero signum, it will return = 0 

以下程序说明了Java.lang.Integer.signum()方法。

程序1 :

// Java program to illustrate the// Java.lang.Integer.signum() Methodimport java.lang.*; public class Geeks { public static void main(String[] args) {     // It will return 1 as  the int value is greater than 1    System.out.println(Integer.signum(1726));     // It will return -1 as  the int value is less than 1    System.out.println(Integer.signum(-13));     // It will returns 0 as int value is equal to 0    System.out.println(Integer.signum(0));}}

输出

1-10

程序2

// Java program to illustrate the// Java.lang.Integer.signum() Methodimport java.lang.*; public class Geeks { public static void main(String[] args) {     // It will return 1 as  the int value is greater than 1    System.out.println(Integer.signum(-1726));     // It will return -1 as  the int value is less than 1    System.out.println(Integer.signum(13));     // It will returns 0 as int value is equal to 0    System.out.println(Integer.signum(0));}}

输出

-110

程序3： 对于一个十进制值和字符串。
注意： 当十进制值和字符串作为参数传递时，会返回错误信息。

// Java program to illustrate the// Java.lang.Integer.signum() Methodimport java.lang.*; public class Geeks { public static void main(String[] args) {     //returns compile time error as passed argument is a decimal value    System.out.println(Integer.signum(3.81));              //returns compile time error as passed argument is a string    System.out.println(Integer.signum("77"));  }}

输出

prog.java:10: error: incompatible types: possible lossy conversion from double to int    System.out.println(Integer.signum(3.81));                                      ^prog.java:14: error: incompatible types: String cannot be converted to int    System.out.println(Integer.signum("77"));                                      ^Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output2 errors