While Loops

Loops let you repeat a block of code multiple times. The while loop repeats as long as a condition is true.

Basic While Loop

let count = 1;

while (count <= 5) {
    console.log("Count:", count);
    count++;
}
// Output: Count: 1, Count: 2, ... Count: 5

How It Works

1. Check the condition
2. If true, run the code block
3. Go back to step 1
4. If false, exit the loop

Infinite Loop Warning

// DON'T DO THIS — infinite loop!
while (true) {
    console.log("Forever...");
}

// Always make sure the condition will eventually become false!

Do...While Loop

The do...while loop runs the code at least once before checking the condition:

let num = 10;

do {
    console.log("Number:", num);
    num++;
} while (num <= 5);

// Output: "Number: 10" — runs once even though 10 > 5

Practical Example

// Simple guessing game concept
let secretNumber = 7;
let guess = 0;
let attempts = 0;

while (guess !== secretNumber) {
    guess = Math.floor(Math.random() * 10) + 1;
    attempts++;
}

console.log(`Found ${secretNumber} in ${attempts} attempts!`);