How nodejs executes js files

By using the require() function, you can execute JS files in Node.js. The specific steps are as follows: Create a JS file, write the code and save it. In the Node.js file, use the require() function to load the JS file. Once the file is loaded, you can access the functions and variables defined in the JS file.

How to use Node.js to execute JS files

In Node.js, you can use require() function to execute JS files.

Steps:

1. Create JS file: Write code in the JS file to be executed. For example, a file named script.js:

<code class="js">console.log('Hello, world!');</code>

2. Load the file using require(): In the Node.js file, Use the require() function to load the JS file. File paths need to be relative to the current working directory. For example:

<code class="js">const script = require('./script.js');</code>

3. Execute code: After loading the file, you can access the functions and variables defined in the JS file. For example, to execute the console.log() statement, you can use:

<code class="js">script.console.log('Hello, world!');</code>

Details:

• require() The function returns an object containing all the values ​​exported in the loaded JS file.
• If the JS file does not export any values, require() will return an empty object.
• require() is also a caching mechanism, which means that files loaded once will not be loaded again.
• The scope of the loaded JS file is limited to the Node.js file that loaded it.

Example:

The following code example demonstrates how to execute a JS file in Node.js:

<code class="js">// 在脚本文件中定义了一个函数
// script.js
function greet(name) {
  console.log(`Hello, ${name}!`);
}

// 在 Node.js 文件中加载脚本文件
// app.js
const script = require('./script.js');

// 执行脚本文件中的函数
script.greet('John');</code>

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