71 lines
2.4 KiB
Markdown
71 lines
2.4 KiB
Markdown
---
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title: Object getOwnPropertyNames
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---
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The `Object.getOwnPropertyNames()` method returns an array of all properties (enumerable or not) found directly upon a given object.
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## Syntax
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Object.getOwnPropertyNames(obj)
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### Parameters
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**obj**
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The object whose enumerable _and non-enumerable_ own properties are to be returned.
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<a href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/getOwnPropertyNames' target='_blank' rel='nofollow'>MDN link</a> | <a href='https://msdn.microsoft.com/en-us/LIBRary/ff688126%28v=vs.94%29.aspx' target='_blank' rel='nofollow'>MSDN link</a>
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## Description
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`Object.getOwnPropertyNames()` returns an array whose elements are strings corresponding to the enumerable _and non-enumerable_ properties found directly upon object. 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.
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## Examples
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var arr = ['a', 'b', 'c'];
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console.log(Object.getOwnPropertyNames(arr).sort()); // logs '0,1,2,length'
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// Array-like object
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var obj = { 0: 'a', 1: 'b', 2: 'c' };
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console.log(Object.getOwnPropertyNames(obj).sort()); // logs '0,1,2'
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// Logging property names and values using Array.forEach
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Object.getOwnPropertyNames(obj).forEach(function(val, idx, array) {
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console.log(val + ' -> ' + obj[val]);
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});
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// logs
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// 0 -> a
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// 1 -> b
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// 2 -> c
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// non-enumerable property
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var my_obj = Object.create({}, {
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getFoo: {
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value: function() { return this.foo; },
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enumerable: false
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}
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});
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my_obj.foo = 1;
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console.log(Object.getOwnPropertyNames(my_obj).sort()); // logs 'foo,getFoo'
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function Pasta(grain, size, shape) {
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this.grain = grain;
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this.size = size;
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this.shape = shape;
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}
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var spaghetti = new Pasta("wheat", 2, "circle");
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var names = Object.getOwnPropertyNames(spaghetti).filter(CheckKey);
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document.write(names);
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// Check whether the first character of a string is 's'.
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function CheckKey(value) {
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var firstChar = value.substr(0, 1);
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if (firstChar.toLowerCase() == 's')
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return true;
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else
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return false;
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}
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// Output:
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// size,shape |