Object.prototype.propertyIsEnumerable()

propertyIsEnumerable() 메서드는 특정 속성이 열거가능한지 여부를 나타내는 불리언 값을 반환합니다.

구문

obj.propertyIsEnumerable(prop)

매개변수

prop
테스트 할 속성의 이름.

반환 값

특정 속성이 열거가능한지 여부를 나타내는 Boolean.

설명

모든 객체는 propertyIsEnumerable 메소드를 가지고 있습니다. 이 메소드는 프로토타입 체인을 통해 상속된 특성을 제외하고 개체에 지정된 속성을 for...in 루프로 열거할 수 있는지 여부를 확인할 수 있습니다. 개체에 지정된 속성이 없으면 이 메소드는 false를 반환합니다.

예제

A basic use of propertyIsEnumerable

The following example shows the use of propertyIsEnumerable on objects and arrays:

var o = {};
var a = [];
o.prop = 'is enumerable';
a[0] = 'is enumerable';

o.propertyIsEnumerable('prop');   // returns true
a.propertyIsEnumerable(0);        // returns true

User-defined versus built-in objects

The following example demonstrates the enumerability of user-defined versus built-in properties:

var a = ['is enumerable'];

a.propertyIsEnumerable(0);          // returns true
a.propertyIsEnumerable('length');   // returns false

Math.propertyIsEnumerable('random');   // returns false
this.propertyIsEnumerable('Math');     // returns false

Direct versus inherited properties

var a = [];
a.propertyIsEnumerable('constructor');         // returns false

function firstConstructor() {
  this.property = 'is not enumerable';
}

firstConstructor.prototype.firstMethod = function() {};

function secondConstructor() {
  this.method = function method() { return 'is enumerable'; };
}

secondConstructor.prototype = new firstConstructor;
secondConstructor.prototype.constructor = secondConstructor;

var o = new secondConstructor();
o.arbitraryProperty = 'is enumerable';

o.propertyIsEnumerable('arbitraryProperty');   // returns true
o.propertyIsEnumerable('method');              // returns true
o.propertyIsEnumerable('property');            // returns false

o.property = 'is enumerable';

o.propertyIsEnumerable('property');            // returns true

// These return false as they are on the prototype which 
// propertyIsEnumerable does not consider (even though the last two
// are iteratable with for-in)
o.propertyIsEnumerable('prototype');   // returns false (as of JS 1.8.1/FF3.6)
o.propertyIsEnumerable('constructor'); // returns false
o.propertyIsEnumerable('firstMethod'); // returns false

명세

Specification Status Comment
ECMAScript 3rd Edition (ECMA-262) Standard Initial definition
ECMAScript 5.1 (ECMA-262)
The definition of 'Object.prototype.propertyIsEnumerable' in that specification.
Standard
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'Object.prototype.propertyIsEnumerable' in that specification.
Standard
ECMAScript Latest Draft (ECMA-262)
The definition of 'Object.prototype.propertyIsEnumerable' in that specification.
Draft

브라우저 호환성

Update compatibility data on GitHub
DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
propertyIsEnumerableChrome Full support YesEdge Full support 12Firefox Full support 1IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes

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