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    Object.getOwnPropertyNames Redirect 1

    Summary

    The Object.getOwnPropertyNames() method returns an array of all properties (enumerable or not) found directly upon a given object.

    Syntax

    Object.getOwnPropertyNames(obj)

    Parameters

    obj
    The object whose enumerable and non-enumerable own properties are to be returned.

    Description

    Object.getOwnPropertyNames returns an array whose elements are strings corresponding to the enumerable and non-enumerable properties found directly upon obj. The ordering of the enumerable properties in the array is consistent with the ordering exposed by a for...in loop (or by Object.keys) over the properties of the object. The ordering of the non-enumerable properties in the array, and among the enumerable properties, is not defined.

    Examples

    var arr = ["a", "b", "c"];
    print(Object.getOwnPropertyNames(arr).sort()); // prints "0,1,2,length"
    
    // Array-like object
    var obj = { 0: "a", 1: "b", 2: "c"};
    print(Object.getOwnPropertyNames(obj).sort()); // prints "0,1,2"
    
    // Printing property names and values using Array.forEach
    Object.getOwnPropertyNames(obj).forEach(function(val, idx, array) {
      print(val + " -> " + obj[val]);
    });
    // prints
    // 0 -> a
    // 1 -> b
    // 2 -> c
    
    // non-enumerable property
    var my_obj = Object.create({}, { getFoo: { value: function() { return this.foo; }, enumerable: false } });
    my_obj.foo = 1;
    
    print(Object.getOwnPropertyNames(my_obj).sort()); // prints "foo, getFoo"
    

    If you want only the enumerable properties, see Object.keys or use a for...in loop (although note that this will return enumerable properties not found directly upon that object but also along the prototype chain for the object unless the latter is filtered with hasOwnProperty()).

    Items on the prototype chain are not listed:

    function ParentClass () {
    }
    ParentClass.prototype.inheritedMethod = function () {
    };
    
    function ChildClass () {
      this.prop = 5;
      this.method = function () {};
    }
    ChildClass.prototype = new ParentClass;
    ChildClass.prototype.prototypeMethod = function () {
    };
    
    alert(
      Object.getOwnPropertyNames(
        new ChildClass() // ["prop", "method"]
      )
    )
    

    Specifications

    Specification Status Comment
    ECMAScript 5.1 (ECMA-262)
    The definition of 'Object.getOwnPropertyNames' in that specification.
    Standard Initial definition.
    Implemented in JavaScript 1.8.5
    ECMAScript 6 (ECMA-262)
    The definition of 'Object.getOwnPropertyNames' in that specification.
    Draft  

    Browser compatibility

    Feature Firefox (Gecko) Chrome Internet Explorer Opera Safari
    Basic support 4 (2.0) 5 9 12 5
    Feature Firefox Mobile (Gecko) Android IE Mobile Opera Mobile Safari Mobile
    Basic support ? ? ? ? ?

    Based on Kangax's compat table.

    See also

    Document Tags and Contributors

    Contributors to this page: Sheppy
    Last updated by: Sheppy,