Java - Bitwise XOR and assignment operator

The Bitwise XOR and assignment operator (^=) assigns the first operand a value equal to the result of Bitwise XOR operation of two operands.

(x ^= y) is equivalent to (x = x ^ y)

The Bitwise XOR operator (^) is a binary operator which takes two bit patterns of equal length and performs the logical exclusive OR operation on each pair of corresponding bits. It returns 1 if only one of the bits is 1, else returns 0.

The example below describes how bitwise XOR operator works:

50 ^ 25 returns 43

     50    ->    110010  (In Binary)
   ^ 25    ->  ^ 011001  (In Binary)
    ----        --------
     43    <-    101011  (In Binary)  

The code of using Bitwise XOR and assignment operator (^=) is given below:

public class MyClass {
  public static void main(String[] args) {
    int x = 50;
    int y = 25;

    //Bitwise XOR and assignment operation
    x ^= y;

    //Displaying the result
    System.out.println("x = "+ x);
  }
}

The output of the above code will be:

x = 43

Example: Swap two numbers without using temporary variable

The bitwise XOR and assignment operator can be used to swap the value of two variables. Consider the example below.

public class MyClass {
  static void swap(int x, int y) {
    System.out.println("Before Swap.");
    System.out.println("x = " + x);
    System.out.println("y = " + y);

    //Swap technique
    x ^= y;
    y ^= x;
    x ^= y;

    System.out.println("After Swap.");
    System.out.println("x = " + x);
    System.out.println("y = " + y);
  }

  public static void main(String[] args) {
    swap(10, 25);
  }
}

The above code will give the following output:

Before Swap.
x = 10
y = 25
After Swap.
x = 25
y = 10