Java - Long reverseBytes() method

---

---

Description

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

Declaration

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

public static long reverseBytes(long i)

Parameters

i − This is the long value.

Return Value

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

Exception

NA

Example 1

The following example shows the usage of Long reverseBytes() method to get an long by reversing the order of the bytes 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 bit count and then value obtained by reversing order of the bytes in the specified long value using reverseBytes() 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-bit
      System.out.println("Number of one bit = " + Long.bitCount(i)); 

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

Output

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

Number = 170
Binary = 10101010
Number of one bit = 4
After reversing = -6196953087261802496

Example 2

The following example shows the usage of Long reverseBytes() method to get an long by reversing the order of the bytes 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 bit count and then value obtained by reversing order of the bytes in the specified long value using reverseBytes() 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-bit
      System.out.println("Number of one bit = " + Long.bitCount(i)); 

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

Output

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

Number = -170
Binary = 1111111111111111111111111111111111111111111111111111111101010110
Number of one bit = 60
After reversing = 6269010681299730431

Example 3

The following example shows the usage of Long reverseBytes() method to get an long by reversing the order of the bytes 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 bit count and then value obtained by reversing order of the bytes in the specified long value using reverseBytes() 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-bit
      System.out.println("Number of one bit = " + Long.bitCount(i)); 

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

Output

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

Number = 0
Binary = 0
Number of one bit = 0
After reversing = 0