UglifyJS is a powerful toolkit developed to parse, mangle, compress, and beautify JavaScript code. It supports most ECMAScript features and is particularly useful for optimizing JavaScript files to improve web page load speeds. However, it's important to note that for more complex features of ECMAScript, using transpilers like Babel first is recommended.

How do you use uglify-js?

To use the UglifyJS JavaScript library, make sure to install the Node.js framework first, and then can install UglifyJS. Installing UglifyJS for usage as a command line application is as easy as running npm install uglify-js -g, and for programmatic use, run npm install uglify-js.

Once installed, you can utilize UglifyJS in the command line with this format: uglifyjs [input files] [options]. If you were to use this in a JavaScript application, you would first require the module using var UglifyJS = require("uglify-js");. Once imported, you can use the available UglifyJS methods for compressing, beautifying, or mangling your JavaScript code. For instance, compressing your JavaScript code with UglifyJS is as easy as following the example below:

var code = "function add(first, second) { return first + second; }";
var result = UglifyJS.minify(code);
console.log(result.code);

This example takes your input code, minifies it, and the result is then logged to the console.

Where are the uglify-js docs?

The UglifyJS documentation can be found on the GitHub repository. The repository contains detailed instructions and examples both for CLI usage and programmatic usage of the UglifyJS module. Make sure to reference the API section in the readme file for detailed descriptions of the available functions and options within UglifyJS.