Day 4 Operators
Operators se hum values par operations karte hain — calculate karna, compare karna, ya combine karna.
Arithmetic Operators
Basic math operations ke liye arithmetic operators use hote hain.
let a = 10, b = 3;
console.log(a + b); // 13 — addition
console.log(a - b); // 7 — subtraction
console.log(a * b); // 30 — multiplication
console.log(a / b); // 3.33 — division
console.log(a % b); // 1 — modulus (remainder)
console.log(a ** b); // 1000 — exponentiation (10³)
// Increment / Decrement
let x = 5;
x++; // x = 6
x--; // x = 5
++x; // x = 6 (pre-increment)
Comparison Operators
Compare karte hain aur true/false return karte hain.
// == vs === ← very important!
console.log(5 == "5"); // true (value only — type ignore)
console.log(5 === "5"); // false (value + type — strict)
console.log(5 !== "5"); // true
// Hamesha === use karo!
console.log(10 > 5); // true
console.log(10 < 5); // false
console.log(10 >= 10); // true
console.log(10 <= 9); // false
Logical Operators
Multiple conditions combine karne ke liye.
// && (AND) — dono true hona chahiye
let age = 20;
let hasID = true;
console.log(age >= 18 && hasID); // true
// || (OR) — ek bhi true ho
let isAdmin = false;
let isMember = true;
console.log(isAdmin || isMember); // true
// ! (NOT) — opposite
console.log(!true); // false
console.log(!false); // true
// Nullish Coalescing (??) — null/undefined check
let username = null;
let display = username ?? "Guest";
console.log(display); // "Guest"
🎯 Practice Challenge
Calculator banao: do numbers lo, add/subtract/multiply/divide karo, aur results console mein print karo.