Новое в JavaScript 1.8.5

JavaScript версии 1.8.5 включен в Firefox 4.

New functions

Function	Description
`Object.create`	Создает новый объект с указанным объекта-прототипа и свойств.bug 492840
`Object.defineProperty`	Добавляет имя свойства, описанное в данной дескриптор к объекту.
`Object.defineProperties`	Adds the named properties described by the given descriptors to an object.
`Object.getOwnPropertyDescriptor`	Returns a property descriptor for a named property on an object. bug 505587
`Object.keys`	Returns an array of all enumerable properties on an object. bug 307791
`Object.getOwnPropertyNames`	Returns an array of all enumerable and non-enumerable properties on an object. bug 518663
`Object.preventExtensions`	Prevents any extensions of an object. bug 492849
`Object.isExtensible`	Determine if extending of an object is allowed. bug 492849
`Object.seal`	Prevents other code from deleting properties of an object. bug 492845
`Object.isSealed`	Determine if an object is sealed. bug 492845
`Object.freeze`	Freezes an object: other code can't delete or change any properties. bug 492844
`Object.isFrozen`	Determine if an object was frozen. bug 492844
`Array.isArray`	Checks if a variable is an array. bug 510537
`Date.toJSON`	Returns a JSON format string for a `Date` object.
`Function.prototype.bind`	Creates a new function that, when called, itself calls this function in the context provided (with a given sequence of arguments) bug 429507

New ECMAScript5 features

get and set operators now allows the identifier to be numeric or a string. bug 520696
Function.apply() can accept any array-like object as the arguments list, instead of only true arrays.
strict mode support
Array.toString() now works even on non-arrays by either returning the result of calling its join() method if one is available or by calling its toString() method.

Other standardization work

Various non-standard syntaxes for defining getters and setters have been removed; ECMAScript 5 defined syntax has not been changed. These were all pretty esoteric and rarely used; if this affects you, see this blog post for details.

New objects

Object	Description
`Proxy`	Offers support for creating `Object` and `Function` proxies that enable meta-programming in JavaScript.

Changes to global objects

ISO 8601 support in Date: The Date object's parse() method now supports simple ISO 8601 format date strings.
Global objects made read only: The NaN, Infinity, and undefined global objects have been made read only, per the ECMAScript 5 specification.

Additional changes

obj.__parent__ and obj.__count__ become obsolete. Some information about why: SpiderMonkey change du jour: the special __parent__ property has been removed bug 551529 & bug 552560.
Trailing commas no longer accepted in JSON.parse().

JavaScript (SpiderMonkey) API changes

Note: Locale callbacks (as specified in the JSLocaleCallbacks structure) should not free the memory buffer passed to them; this buffer is managed by the SpiderMonkey runtime.

The JS_NewString() function was removed in SpiderMonkey 1.8.5. Use JS_NewStringCopyN() instead.