Swap Two Numbers

// Method 1: Using a temporary variable
let a = 5;
let b = 10;
console.log("Before swap: a =", a, ", b =", b);

let temp = a;
a = b;
b = temp;
console.log("After swap: a =", a, ", b =", b);

// Method 2: Using destructuring (ES6 - Modern approach)
let x = 5;
let y = 10;
console.log("Before swap: x =", x, ", y =", y);

[x, y] = [y, x];
console.log("After swap: x =", x, ", y =", y);

// Method 3: Using arithmetic (without temp variable)
let p = 5;
let q = 10;
console.log("Before swap: p =", p, ", q =", q);

p = p + q;
q = p - q;
p = p - q;
console.log("After swap: p =", p, ", q =", q);

Before swap: a = 5 , b = 10
After swap: a = 10 , b = 5
Before swap: x = 5 , y = 10
After swap: x = 10 , y = 5
Before swap: p = 5 , q = 10
After swap: p = 10 , q = 5

This program demonstrates different methods to swap two variable values in JavaScript.

Method 1: Temporary Variable

The most straightforward and readable approach:

1. Store first value in temporary variable
2. Assign second value to first variable
3. Assign temporary value to second variable

Pros:

• Easy to understand
• Works with any data type
• Most readable

Cons:

• Requires extra memory for temp variable

Method 2: Destructuring Assignment (ES6)

Modern JavaScript feature that's clean and elegant:

javascript
[a, b] = [b, a];

How it works:

• Creates an array with swapped values
• Destructures into variables
• All in one line!

Pros:

• Concise and modern
• No temporary variable needed
• Works with any data type
• Most elegant solution

Cons:

• Requires ES6 support
• Slightly less intuitive for beginners

Method 3: Arithmetic Swap

Uses addition and subtraction (only works with numbers):

javascript
a = a + b;
b = a - b;
a = a - b;

Pros:

• No temporary variable
• Works with numbers

Cons:

• Only works with numbers
• Risk of overflow with large numbers
• Less readable

When to Use:

• Method 1: General purpose, most readable

• Method 2: Modern code, any data type

• Method 3: Only for numbers, when memory is critical