Integer signum() Method in Java (original) (raw)

Last Updated : 19 Aug, 2021

The signum function is an odd mathematical function that extracts the sign of a real number. The signum function is also known as sign function.
The Integer.signum() method of java.lang returns the signum function of the specified integer value. For a positive value, a negative value and zero the method returns 1, -1 and 0 respectively.

Syntax :

public static int signum(int a)

Parameter: The method takes one parameter a of integer type on which the operation is to be performed.

Return Value: The method returns the signum function of the specified integer value. If the specified value is negative it returns -1, 0 if the specified value is zero, and 1 if the specified value is positive.

Examples:

Consider an integer a = 27 Since 27 is a positive int signum will return= 1

Consider another integer a = -61 Since -61 is a negative int signum will return= -1

Consider the integer value a = 0 For a zero signum, it will return = 0

Below programs illustrate the Java.lang.Integer.signum() Method:

Program 1:

Java `

// Java program to illustrate the // Java.lang.Integer.signum() Method import 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));

} }

`

Program 2:

Java `

// Java program to illustrate the // Java.lang.Integer.signum() Method import 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));

} }

`

Program 3: For a decimal value and string.
Note: It returns an error message when a decimal value and string is passed as an argument.

Java `

// Java program to illustrate the // Java.lang.Integer.signum() Method import 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"));

} }

`

Output:

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 output 2 errors