react.dev

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id	title	layout	next
getting-started	Getting Started	docs	tutorial.html

JSFiddle

The easiest way to start hacking on React is using the following JSFiddle Hello World examples:

Starter Kit

Download the starter kit to get started.

Download Starter Kit {{site.react_version}}

In the root directory of the starter kit, create a helloworld.html with the following contents.

<!DOCTYPE html>
<html>
  <head>
    <script src="build/react.js"></script>
    <script src="build/JSXTransformer.js"></script>
  </head>
  <body>
    <div id="example"></div>
    <script type="text/jsx">
      /** @jsx React.DOM */
      React.renderComponent(
        <h1>Hello, world!</h1>,
        document.getElementById('example')
      );
    </script>
  </body>
</html>

The XML syntax inside of JavaScript is called JSX; check out the JSX syntax to learn more about it. In order to translate it to vanilla JavaScript we use <script type="text/jsx"> and include JSXTransformer.js to actually perform the transformation in the browser.

Separate File

Your React JSX code can live in a separate file. Create the following src/helloworld.js.

/** @jsx React.DOM */
React.renderComponent(
  <h1>Hello, world!</h1>,
  document.getElementById('example')
);

Then reference it from helloworld.html:

<script type="text/jsx" src="src/helloworld.js"></script>

Offline Transform

First install the command-line tools (requires npm):

npm install -g react-tools

Then, translate your src/helloworld.js file to plain JavaScript:

jsx --watch src/ build/

The file build/helloworld.js is autogenerated whenever you make a change.

/** @jsx React.DOM */
React.renderComponent(
  React.DOM.h1(null, 'Hello, world!'),
  document.getElementById('example')
);

Note:

The comment parser is very strict right now; in order for it to pick up the @jsx modifier, two conditions are required. The @jsx comment block must be the first comment on the file. The comment must start with /** (/* and // will not work). If the parser can't find the @jsx comment, it will output the file without transforming it.

Update your HTML file as below:

<!DOCTYPE html>
<html>
  <head>
    <title>Hello React!</title>
    <script src="build/react.js"></script>
    <!-- No need for JSXTransformer! -->
  </head>
  <body>
    <div id="example"></div>
    <script src="build/helloworld.js"></script>
  </body>
</html>

Want CommonJS?

If you want to use React with browserify, webpack, or another CommonJS-compatible module system, just use the react npm package. In addition, the jsx build tool can be integrated into most packaging systems (not just CommonJS) quite easily.

Next Steps

Check out the tutorial and the other examples in the starter kit's examples directory to learn more. Good luck, and welcome!

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