JavaScript

Article
10/20/2016

Windows Internet Explorer 8 introduced native JavaScript Object Notation (JSON) support for JavaScript objects and accessor support for DOM objects. In addition to improved JavaScript performance,Windows Internet Explorer 9 added support for many more ECMAScript Language Specification, 5th edition features. Internet Explorer 10 introduces support for Typed Arrays and ECMAScript 5 (ES5) strict mode. For more information, see JavaScript Version Information

ECMAScript 5

There are a number of important ECMAScript 5 features implemented in Internet Explorer 9, including the following:

New array methods: every, filter, forEach, indexOf, isArray, lastIndexOf, map, reduce, reduceRight, some
Enhanced object model and object functions: Object.create, Object.defineProperties, Object.defineProperty, Object.freeze, Object.getOwnPropertyDescriptor, Object.getOwnPropertyNames, Object.getPrototypeOf, Object.isExtensible, Object.isFrozen, Object.isSealed, Object.keys, Object.preventExtensions, Object.seal
Other computational methods and functions: Date.now, Date.parse support for ISO Date Format, Date.toISOString, Function bind, String trim

Internet Explorer 9 also corrects several issues present in the previous implementations of JavaScript in Windows Internet Explorer. For more information, see "Enhanced Scripting in IE9: ECMAScript 5 Support and More".

In this section

Topic	Description
ES5 strict mode	ECMAScript is the emerging standard for JavaScript, defined by the ECMA-262 specification. The fifth edition was published in December 2009, and adds strict mode for more robust error checking.
Typed arrays	You can use typed arrays to handle binary data from sources such as network protocols, binary file formats, and raw graphics buffers. Typed arrays can also be used to manage in-memory binary data with well-known byte layouts.