Swapping Two Variables in Java Without a Temporary Variable

Swapping two variables is a common task in programming. This guide shows how to do it in Java without a temporary variable.

Methods covered:

Arithmetic addition and subtraction

Multiplication and division

Bitwise XOR

Method 1: Arithmetic

package com.mkyong;
public class SwapWithoutTemp {
    public static void main(String[] args) {
        int a = 10, b = 20;
        System.out.println("Before: a = " + a + ", b = " + b);
        a = a + b;
        b = a - b;
        a = a - b;
        System.out.println("After: a = " + a + ", b = " + b);
    }
}

Explanation of each step and a note about possible integer overflow when the sum exceeds Integer.MAX_VALUE .

Method 2: Multiplication/Division

package com.mkyong;
public class SwapUsingMultiplication {
    public static void main(String[] args) {
        int a = 10, b = 20;
        System.out.println("Before: a = " + a + ", b = " + b);
        a = a * b;
        b = a / b;
        a = a / b;
        System.out.println("After: a = " + a + ", b = " + b);
    }
}

This method works only when neither variable is zero and may overflow for large numbers.

Method 3: Bitwise XOR

package com.mkyong;
public class SwapUsingXOR {
    public static void main(String[] args) {
        int x = 10, y = 20;
        System.out.println("Before: x = " + x + ", y = " + y);
        x = x ^ y;
        y = x ^ y;
        x = x ^ y;
        System.out.println("After: x = " + x + ", y = " + y);
    }
}

The XOR technique needs no extra memory, avoids overflow, but is less readable and works only with integer types.

Advantages of XOR: no temporary variable, no overflow risk, fast bit operation. Disadvantages: lower readability, not suitable for floating‑point numbers, harder to debug.

Choosing a method depends on the data range and readability requirements; for most cases the arithmetic method is simple, while XOR is useful when memory usage is critical.

Reference: https://mkyong.com/java/java-swap-two-variables-without-a-temp-variable (tested with Java 21).