JavaScript can be used to develop various types of web applications, including single page applications (SPA) and Responsive web applications. Through frameworks such as React, Angular, Vue.js, etc., developers can use JavaScript to build complex front-end applications. The following is an example of a simple counter developed using the React framework: <\/p>

import React, { useState } from \"react\";\n\nfunction Counter() {\n  const [count, setCount] = useState(0);\n\n  return (\n    
\n      
Count: {count}<\/p>\n      

In addition to being widely used in front-end development, JavaScript can also be used for back-end development. Node.js is a JavaScript-based runtime environment that allows JavaScript to run on the server side and provides the functions required for back-end development. The following is a simple Node.js server code example: <\/p>

const http = require('http');\n\nconst server = http.createServer((req, res) => {\n  res.statusCode = 200;\n  res.setHeader('Content-Type', 'text\/plain');\n  res.end('Hello, World!\n');\n});\n\nserver.listen(3000, '127.0.0.1', () => {\n  console.log('Server running at http:\/\/127.0.0.1:3000\/');\n});<\/pre>
4. Game development<\/h3>
JavaScript can also be used to develop simple Web games. Through technologies such as Canvas or WebGL, various kind of game effect. The following is a simple example of using Canvas to draw graphics: <\/p>
\n\n\n