Java - Long reverse() method

Description

The Java Long reverse() method returns the value obtained by reversing the order of the bits in the two's complement binary representation of the specified long value.

Declaration

Following is the declaration for java.lang.Long.reverse() method

public static long reverse(long i)

Parameters

i − This is the long value.

Return Value

This method returns the value obtained by reversing order of the bits in the specified long value.

Exception

NA

Example 1

The following example shows the usage of Long reverse() method to get an long by reversing the order of the bits in the two's complement binary representation of the specified long value. We've created a long variable and assigned it a positive long value. Then using toBinaryString() method, we're printing the binary format of the value. Using bitCount(), we're printing the one bits count and then value obtained by reversing order of the bits in the specified long value using reverse() method.

package com.tutorialspoint;
public class LongDemo {
   public static void main(String[] args) {
      long i = 170L;
      System.out.println("Number = " + i);

      /* returns the string representation of the unsigned long value 
         represented by the argument in binary (base 2) */
      System.out.println("Binary = " + Long.toBinaryString(i));

      // returns the number of one-bits 
      System.out.println("Number of one bits = " + Long.bitCount(i)); 

      /*  returns the value obtained by reversing order of the bits in 
         the specified long value */ 
      System.out.println("After reversing = " + Long.reverse(i));
   }
}

Output

Let us compile and run the above program, this will produce the following result −

Number = 170
Binary = 10101010
Number of one bits = 4
After reversing = 6124895493223874560

Example 2

The following example shows the usage of Long reverse() method to get an long by reversing the order of the bits in the two's complement binary representation of the specified negative long value. We've created a long variable and assigned it a positive long value. Then using toBinaryString() method, we're printing the binary format of the value. Using bitCount(), we're printing the one bits count and then value obtained by reversing order of the bits in the specified long value using reverse() method.

package com.tutorialspoint;
public class LongDemo {
   public static void main(String[] args) {
      long i = -170L;
      System.out.println("Number = " + i);

      /* returns the string representation of the unsigned long value 
         represented by the argument in binary (base 2) */
      System.out.println("Binary = " + Long.toBinaryString(i));

      // returns the number of one-bits 
      System.out.println("Number of one bits = " + Long.bitCount(i)); 

      /*  returns the value obtained by reversing order of the bits in 
         the specified long value */ 
      System.out.println("After reversing = " + Long.reverse(i));
   }
}

Output

Let us compile and run the above program, this will produce the following result −

Number = -170
Binary = 1111111111111111111111111111111111111111111111111111111101010110
Number of one bits = 60
After reversing = 7710162562058289151

Example 3

The following example shows the usage of Long reverse() method to get an long by reversing the order of the bits in the two's complement binary representation of the specified zero value. We've created a long variable and assigned it a positive long value. Then using toBinaryString() method, we're printing the binary format of the value. Using bitCount(), we're printing the one bits count and then value obtained by reversing order of the bits in the specified long value using reverse() method.

package com.tutorialspoint;
public class LongDemo {
   public static void main(String[] args) {
      long i = 0L;
      System.out.println("Number = " + i);

      /* returns the string representation of the unsigned long value 
         represented by the argument in binary (base 2) */
      System.out.println("Binary = " + Long.toBinaryString(i));

      // returns the number of one-bits 
      System.out.println("Number of one bits = " + Long.bitCount(i)); 

      /*  returns the value obtained by reversing order of the bits in 
         the specified long value */ 
      System.out.println("After reversing = " + Long.reverse(i));
   }
}

Output

Let us compile and run the above program, this will produce the following result −

Number = 0
Binary = 0
Number of one bits = 0
After reversing = 0
java_lang_long.htm
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