Object

요약

객체 레퍼 생성.

문법

new Object( [ value ] )

파라미터

value

자바스크립트 모든 값이 허용.

설명

The Object constructor creates an object wrapper for the given value. If the value is null or undefined, it will create and return an empty object, otherwise, it will return an object of a type that corresponds to the given value.

I'm pretty sure the following is true. The only difference I can see according to the spec is that when called as a constructor, there are provisions to handle host objects differently than simply returning themWhen called in a non-constructor context, Object behaves identically.

Properties

For properties available on Object instances, see Properties of Object instances.

prototype

Object 타입의 모든 객체에게 다른 속성들을 추가할 수 있게 한다.

Methods

For methods available on Object instances, see Methods of Object instances.

create

Requires JavaScript 1.8.5

특정 프로토타입 객체와 속성을 가진 새로운 객체를 만듬
Creates a new object with the specified prototype object and properties.

defineProperty

Requires JavaScript 1.8.5
Adds the named property described by a given descriptor to an object.

defineProperties

Requires JavaScript 1.8.5
Adds the named properties described by the given descriptors to an object.

getOwnPropertyDescriptor

Requires JavaScript 1.8.5
Returns a property descriptor for a named property on an object.

keys

Requires JavaScript 1.8.5
Returns an array containing the names of all of the given object's own enumerable properties.

getOwnPropertyNames

Requires JavaScript 1.8.5
Returns an array containing the names of all of the given object's own enumerable and non-enumerable properties.

getPrototypeOf

Requires JavaScript 1.8.1
Returns the prototype of the specified object.

preventExtensions

Requires JavaScript 1.8.5
Prevents any extensions of an object.

isExtensible

Requires JavaScript 1.8.5
Determine if extending of an object is allowed.

seal

Requires JavaScript 1.8.5
Prevents other code from deleting properties of an object.

isSealed

Requires JavaScript 1.8.5
Determine if an object is sealed.

freeze

Requires JavaScript 1.8.5
Freezes an object: other code can't delete or change any properties.

isFrozen

Requires JavaScript 1.8.5
Determine if an object was frozen.

Object instances

All objects in JavaScript are descended from Object; all objects inherit methods and properties from Object.prototype, although they may be overridden. For example, other constructors' prototypes override the constructor property and provide their own toString methods. Changes to the Object prototype object are propagated to all objects unless the properties and methods subject to those changes are overridden further along the prototype chain.

Properties

constructor

Specifies the function that creates an object's prototype.

__count__

Obsolete since JavaScript 1.8.5
Returns the number of enumerable properties directly on a user-defined object.

__parent__

Obsolete since JavaScript 1.8.5
Points to an object's context.

__proto__

Non-standard
Points to the object which was used as prototype when the object was instantiated.

Methods

constructor

Specifies the function that creates an object's prototype.

__count__

Obsolete since JavaScript 1.8.5
Returns the number of enumerable properties directly on a user-defined object.

__parent__

Obsolete since JavaScript 1.8.5
Points to an object's context.

__proto__

Non-standard
Points to the object which was used as prototype when the object was instantiated.

Examples

Example: Using Object given undefined and null types

The following examples store an empty Object object in o:

var o = new Object();

var o = new Object(undefined);

var o = new Object(null);

Example: Using Object to create Boolean objects

The following examples store Boolean objects in o:

// equivalent to o = new Boolean(true);
var o = new Object(true);

// equivalent to o = new Boolean(false);
var o = new Object(Boolean());

Browser compatibility