How do you loop inside React JSX?

Naveera A.

The Problem

You have a set of elements, and you’d like to loop over them to generate a JSX partial.

In templating languages, you can write a for loop directly inside the template. For example, you can use the following code to loop over a list in Jinja:

{% for i in range(11) %} <li>{{ i }}</li> {% endfor %}

How can you do the same thing using JSX?

The Solution

Two ways you can loop inside JSX are using traditional loops or using the map() method.

Using Traditional Loops

If you have a set of elements, you can use normal JavaScript for, for of, and for in loops outside the return block.

Inside the return block, you can use the resulting array.

You can loop over an array and create JSX partials like so:

import React from "react"; function App() { const seasons = ["Spring", "Summer", "Autumn", "Winter"]; let seasonsList = []; seasons.forEach((season, index) => { seasonsList.push(<li key={index}>{season}</li>); }); return ( <div> <h2>Seasons of the year</h2> <ul>{seasonsList}</ul> </div> ); } export default App;

Using the map() Method

You can use the map() method on an array to loop through the elements and create components, or generate JSX, inside the return block.

import React from "react"; function App() { const seasons = ["Spring", "Summer", "Autumn", "Winter"]; return ( <div> <h2>Seasons of the year</h2> <ul> { => ( <li key={}>{season}</li> ))} </ul> </div> ); } export default App;

Many developers prefer using map() to loop over arrays.

Join the discussionCome work with us
Share on Twitter
Bookmark this page
Ask a questionImprove this Answer

Related Answers

A better experience for your users. An easier life for your developers.

© 2023 • Sentry is a registered Trademark
of Functional Software, Inc.