Strict mode. Strict Mode Overview Note: Sometimes you'll see the default, non-strict mode referred to as "sloppy mode".
This isn't an official term, but be aware of it, just in case. JavaScript's strict mode, introduced in ECMAScript 5, is a way to opt in to a restricted variant of JavaScript, thereby implicitly opting-out of "sloppy mode". Strict mode isn't just a subset: it intentionally has different semantics from normal code. Strict mode - JavaScript. Ecma-262.pdf (application/pdf Object) JavaScript Reference. This part of the JavaScript section on MDN serves as a repository of facts about the JavaScript language. Read more about this reference. Global objects This chapter documents all the JavaScript standard built-in objects, along with their methods and properties.
Value properties. JavaScript Guide. The JavaScript Guide shows you how to use JavaScript and gives an overview of the language. If you need exhaustive information about a language feature, have a look at the JavaScript reference. This Guide is divided into the following chapters.
Introduction Grammar and types Control flow and error handling.