JavaScript Functions Guide
Functions are reusable blocks of code. JavaScript functions are first-class objects — they can be assigned to variables, passed as arguments, and returned from other functions. The guide walks through Calling Functions, Function Properties, Arrow Functions. `call()` invokes a function with a specific `this` value and arguments listed individually. `apply()` does the same with arguments as an array. `bind()` creates a new function with bound `this`. `name` property returns the function name. `length` returns the number of formal parameters. `toString()` returns the function source code. `prototype` exists on constructor functions. The guide is organized into 3 sections that build on each other, each pairing a prose explanation with runnable code. Browse the individual methods covered by this guide in the Functions category. Key APIs covered include Function.prototype.call(), Function.prototype.apply(), Function.prototype.bind(), Function.prototype.toString(), Function.length, Function.name. Related guides: Arrays, Strings, Numbers, Math, Date.