JavaScript Garden

Documentation about the most quirky parts of the JS programming language.

JavaScript Garden is a growing collection of documentation about the most quirky parts of the JavaScript programming language. It gives advice to avoid common mistakes and subtle bugs, as well as performance issues and bad practices, that non-expert JavaScript programmers may encounter on their endeavours into the depths of the language.

JavaScript Garden does not aim to teach you JavaScript. Former knowledge of the language is strongly recommended in order to understand the topics covered in this guide. In order to learn the basics of the language, please head over to the excellent guide on the Mozilla Developer Network.

Table of Content

Intro

Object Usage and Properties

The Prototype

hasOwnProperty

The "for in" Loop

Function Declarations and Expressions

How "this" Works

Closures and References

The "arguments" Object

Constructors

Scopes and Namespaces

Array Iteration and Properties

The "Array" Constructor

Equality and Comparisons

The "typeof" Operator

The "instanceof" Operator

Type Casting

Why Not to Use "eval"

undefined and "null"

Automatic Semicolon Insertion

The "delete" Operator

setTimeout and "setInterval"