Day 5

Conditions & If-Else

11 min

JavaScript 100 Days

Conditions se hum program ko decide karwate hain ke kya karna hai. Real life mein bhi hum decisions lete hain — agar barish ho to chai piyo, warna bahar jao.

if / else if / else

Basic decision making structure.

conditions.js

javascript

let score = 75;

if (score >= 90) {
  console.log("A Grade — Excellent!");
} else if (score >= 80) {
  console.log("B Grade — Very Good!");
} else if (score >= 70) {
  console.log("C Grade — Good!");
} else if (score >= 60) {
  console.log("D Grade — Average");
} else {
  console.log("F Grade — Fail");
}
// Output: C Grade — Good!

Ternary Operator

Single line condition ke liye — condition ? true_value : false_value

ternary.js

javascript

let age = 20;
let status = age >= 18 ? "Adult" : "Minor";
console.log(status); // "Adult"

// Nested (avoid karo — hard to read)
let marks = 85;
let grade = marks >= 90 ? "A" : marks >= 80 ? "B" : marks >= 70 ? "C" : "F";
console.log(grade); // "B"

Switch Statement

Ek variable ke multiple exact values check karne ke liye.

switch.js

javascript

let day = "Monday";

switch (day) {
  case "Monday":
  case "Tuesday":
  case "Wednesday":
  case "Thursday":
  case "Friday":
    console.log("Weekday — work time!");
    break;
  case "Saturday":
  case "Sunday":
    console.log("Weekend — chill time!");
    break;
  default:
    console.log("Invalid day");
}

🎯 Practice Challenge

Age checker banao: age leke check karo — bachcha (< 13), teenager (13-17), adult (18+), ya senior (60+).

OperatorsLoops