How to pass parameters to JavaScript files?

There are several ways to pass parameters to JavaScript files:

1. Command-line arguments: When running a JavaScript file from the command line, you can pass parameters to the file by adding them after the file name. For example: node script.js arg1 arg2 arg3. In the JavaScript file, you can access these arguments using the process.argv array, which contains the command-line arguments.
2. Query string parameters: If you’re running the JavaScript file in a web browser, you can pass parameters to the file using the query string of the URL. For example: http://example.com/script.js?param1=value1&param2=value2. In the JavaScript file, you can access these parameters using the location.search property, which contains the query string of the URL.
3. Environment variables: When running a JavaScript file from the command line, you can set environment variables that can be accessed by the file. For example: export VAR1=value1 && node script.js. In the JavaScript file, you can access environment variables using the process.env object.
4. External configuration files: You can store parameters in an external configuration file, such as a JSON or XML file, and read the file in your JavaScript code. For example:

// config.json
{
  "param1": "value1",
  "param2": "value2"
}

// script.js
const config = require('./config.json');
console.log(config.param1); // value1
console.log(config.param2); // value2

In this example, we store the parameters in a config.json file, and use the require statement to read the file in our JavaScript code. The config object now contains the parameters from the file, which we can access using dot notation.