Understanding Loops in JavaScript: For, While, Do-While, Break, and Continue

Hey everyone! Today, let’s dive into an essential topic in JavaScript — loops! If you’ve ever needed to repeat a task multiple times in your code, loops are your best friend. Loops help us automate repetitive tasks efficiently, making our code more concise and readable. Additionally, we’ll explore two important keywords: break and continue, which allow us to control the flow of loops more effectively. Whether you’re just starting or looking to solidify your understanding, this guide will make loops easy to grasp. Let’s get started! What Are Loops in JavaScript? Loops allow us to run a block of code multiple times without writing it repeatedly. Instead of manually repeating an action, we can automate it using loops. JavaScript has four main types of loops: for loop while loop do…while loop for…of loop (useful for arrays) Let’s break them down with examples! 1️⃣ for Loop The for loop is great when you know exactly how many times you want to run a piece of code. How it Works: A for loop has three parts inside the parentheses: Initialization → Set a starting value. Condition → The loop will run while this is true. Update → Changes the value after each iteration. Example: // Print numbers from 1 to 5 for (let i = 1; i

Feb 19, 2025 - 13:53

Understanding Loops in JavaScript: For, While, Do-While, Break, and Continue

Hey everyone! Today, let’s dive into an essential topic in JavaScript — loops! If you’ve ever needed to repeat a task multiple times in your code, loops are your best friend.

Loops help us automate repetitive tasks efficiently, making our code more concise and readable. Additionally, we’ll explore two important keywords: break and continue, which allow us to control the flow of loops more effectively. Whether you’re just starting or looking to solidify your understanding, this guide will make loops easy to grasp. Let’s get started!

What Are Loops in JavaScript?
Loops allow us to run a block of code multiple times without writing it repeatedly. Instead of manually repeating an action, we can automate it using loops.

JavaScript has four main types of loops:

for loop
while loop
do…while loop
for…of loop (useful for arrays)
Let’s break them down with examples!

1️⃣ for Loop
The for loop is great when you know exactly how many times you want to run a piece of code.

How it Works:
A for loop has three parts inside the parentheses:

Initialization → Set a starting value.
Condition → The loop will run while this is true.
Update → Changes the value after each iteration.
Example:
// Print numbers from 1 to 5
for (let i = 1; i <= 5; i++) {
console.log(i);
}
How This Works:
Start with i = 1
Run the loop while i <= 5
Print i, then increase i by 1
Repeat until i is greater than 5

2️⃣ while Loop
The while loop runs as long as the condition is true. It's great when you don’t know beforehand how many times the loop should run.

Example:
// Print numbers from 1 to 5
let i = 1;
while (i <= 5) {
console.log(i);
i++;
}
How This Works:
Check if i <= 5 (if true, run the loop)
Print i
Increase i by 1
Repeat until i is greater than 5

3️⃣ do…while Loop
The do…while loop is similar to while, but it always runs at least once, even if the condition is false!

Example:
// Print numbers from 1 to 5
let i = 1;
do {
console.log(i);
i++;
} while (i <= 5);
How This Works:
Run the code inside {} at least once
Then, check if i <= 5
If true, repeat. If false, stop
Use do...while when you must execute the loop at least once.

4️⃣ for…of Loop (for arrays)
The for...of loop is perfect for iterating over arrays.

Example:
const fruits = ['