"print-an-integer",

"add-two-integers",

"swap-two-numbers",

title: Java Program to Swap Two Numbers

shortTitle: Swap Two Numbers

description: Learn different ways to swap two numbers in Java — using a temporary variable, arithmetic operations, and bitwise XOR — with clear examples and outputs.

Swapping two numbers is a common beginner-friendly exercise in Java. Below are three simple ways to do it:

- Using a temporary variable (safest and most readable)

- Using arithmetic operations (beware of overflow for very large numbers)

- Using bitwise XOR (no temp variable; works for integers)

Before you start, you may want to review:

- [Java Variables and Literals](/docs/variables-and-literals)

- [Java Operators](/docs/operators)

- [Java Basic Input and Output](/docs/basic-input-output)

This is the most straightforward and recommended approach.

class Main {

public static void main(String[] args) {

int a = 10;

int b = 20;

System.out.println("Before swap: a = " + a + ", b = " + b);

int temp = a; // store a

a = b; // put b into a

b = temp; // put original a into b

System.out.println("After swap: a = " + a + ", b = " + b);

}

}

Uses addition and subtraction. Note: This can overflow if the numbers are near the integer limits.

class Main {

public static void main(String[] args) {

int a = 15;

int b = 27;

System.out.println("Before swap: a = " + a + ", b = " + b);

a = a + b; // a becomes sum

b = a - b; // b becomes original a

a = a - b; // a becomes original b

System.out.println("After swap: a = " + a + ", b = " + b);

}

}

Works for integers and avoids extra memory, but is less readable for beginners.

class Main {

public static void main(String[] args) {

int a = 5;

int b = 9;

System.out.println("Before swap: a = " + a + ", b = " + b);

a = a ^ b; // Step 1

b = a ^ b; // Step 2: now b is original a

a = a ^ b; // Step 3: now a is original b

System.out.println("After swap: a = " + a + ", b = " + b);

}

}

- Prefer the temporary variable method for clarity and safety.

- The arithmetic method can be a neat trick, but avoid it when values may overflow.

- XOR is an interesting technique; use it only when it adds real value and readability is not sacrificed.