How to use loops and iteration in JavaScript

What to know about loops and iteration in JavaScript

Looping lets you repeat tasks across arrays, objects, and collections without writing duplicate code. This chapter explains the concept, demonstrates a practical example, and gives you a guided exercise.

How to use loops and iteration in JavaScript

Start with a small function, make inputs and outputs explicit, and test both normal and edge cases. Use browser developer tools to inspect values and errors as you build.

Example: loops and iteration in JavaScript

Use this example as a starting point. Identify the part that controls the result, then adapt it to your own page or project.

for (let index = 0; index < items.length; index += 1) {
  console.log(items[index]);
}

Common questions about loops and iteration

When should I use loops and iteration?

Use this technique when it expresses the structure, styling, or behavior your page needs. Keep the implementation focused and test it with the surrounding content.

What should I practice next?

Build one small interaction that reads a value, validates it, updates the page, and handles an empty or invalid input.