programming - Swap With or Without Third Variable

This is a simple Java program that swaps the values of two numbers using a temporary variable. Let me explain it line by line:

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🔄 Swap Program Explanation

public class Swap {

Defines a public class named Swap.

public static void main(String[] args) {

The main method where the program starts.

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🧮 Variable Initialization

int no1 = 10;
int no2 = 20;

• no1 is assigned the value 10
• no2 is assigned the value 20

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🔁 Swapping Logic Using a Temp Variable

int temp = no1;

• Store the value of no1 (10) in a temporary variable temp.

no1 = no2;

• Now assign the value of no2 (20) to no1.
• So, no1 becomes 20.

no2 = temp;

• Assign the value of temp (10) to no2.
• So, no2 becomes 10.

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🖨️ Output

System.out.println(no1);
System.out.println(no2);

This will print:

20
10

✅ Values have been successfully swapped!

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🔧 Bonus: Swap Without Temp Variable (Just for Fun)

int a = 10, b = 20;
a = a + b;  // a = 30
b = a - b;  // b = 10
a = a - b;  // a = 20

Nice one, Sudhakar! This is a classic example of swapping two numbers without using a temporary variable. Let's break it down step by step:

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🔁 Code Explanation:

public class Swapwithout {

Defines a class called Swapwithout.

public static void main(String[] args) {

Program starts here.

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🧮 Variable Initialization

int no1 = 10;
int no2 = 20;

• no1 is 10
• no2 is 20

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🧠 Swapping Logic (Without Temp Variable)

no1 = no1 + no2;

• no1 becomes 10 + 20 = 30

no2 = no1 - no2;

• no2 becomes 30 - 20 = 10

no1 = no1 - no2;

• no1 becomes 30 - 10 = 20

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✅ Final Values

• no1 = 20
• no2 = 10

System.out.println(no1); // prints 20
System.out.println(no2); // prints 10

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💡 Output:

20
10

📌 Summary:

You've swapped two numbers without using a third variable—just by using arithmetic. Great job!

Let me know if you want to try the same using bitwise XOR method too—it’s another cool trick!