Swap Two Numbers Without a Temp Variable

📌 Definition:

📖 Detailed Explanation:

Arithmetic (a=a+b; b=a-b; a=a-b) or XOR (a^=b; b^=a; a^=b) both avoid a temp. Caveats: arithmetic can overflow, XOR is integer-only, and both zero-out if the two operands are the same variable. In real code a temp (or destructuring/tuple swap) is clearer.

💻 Solutions:

• Java
• JavaScript
• Python

int a = 5, b = 9;
a = a + b;   // 14
b = a - b;   // 5
a = a - b;   // 9

let a = 5, b = 9;
[a, b] = [b, a];   // idiomatic, no temp
// arithmetic: a = a + b; b = a - b; a = a - b;

a, b = 5, 9
a, b = b, a   # tuple swap, no temp

🔑 Key Points:

• Arithmetic swap can overflow
• XOR swap is integer-only
• Both fail if the operands are aliased
• Prefer a temp / tuple swap in real code

🌍 Real-World Example: