Java lang.Long.reverse() method in Java with Examples (original) (raw)

Last Updated : 23 May, 2019

java.lang.Long.reverse() is a built-in function in Java which returns the value obtained by reversing the order of the bits in the two’s complement binary representation of the specified long value.

Syntax:

public static long reverse(long num) Parameter : num - the number passed Returns : the value obtained by reversing the order of the bits in the two's complement binary representation of the specified long value.

Examples:

Input : 254 Output : 9151314442816847872

Input : 8 Output : 1152921504606846976

The program below illustrates the java.lang.Long.reverse() function:

Program 1 :

import java.lang.*;

public class GFG {

public static void main(String[] args)

`` {

`` long l = 8;

`` System.out.println( "The number after reversing bit= "

`` + Long.reverse(l));

`` l = 254;

`` System.out.println( "The number after reversing bit= "

`` + Long.reverse(l));

`` }

}

Output:

The number after reversing bit= 1152921504606846976 The number after reversing bit= 9151314442816847872

Program 2 : When a negative number is passed

import java.lang.*;

public class GFG {

`` public static void main(String[] args)

`` {

`` long l = - 8 ;

`` System.out.println( "The number after reversing bit= "

`` + Long.reverse(l));

`` l = - 254 ;

`` System.out.println( "The number after reversing bit= "

`` + Long.reverse(l));

`` }

}

Output:

The number after reversing bit= 2305843009213693951 The number after reversing bit= 4683743612465315839

Program 3 : When a decimal number is passed

import java.lang.*;

public class GFG {

`` public static void main(String[] args)

`` {

`` System.out.println( "The number after reversing bit= "

`` + Long.reverse( 11.34 ));

`` }

}

Output:

prog.java:16: error: incompatible types: possible lossy conversion from double to long + Long.reverse(11.34));

Program 4 : When a string number is passed

import java.lang.*;

public class GFG {

`` public static void main(String[] args)

`` {

`` System.out.println( "The number after reversing bit= "

`` + Long.reverse( "12" ));

`` }

}

Output:

prog.java:16: error: incompatible types: String cannot be converted to long + Long.reverse("12"));