Created
July 26, 2012 03:27
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Object.keys方法实现
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Object.keys = (function () { | |
var hasOwnProperty = Object.prototype.hasOwnProperty, | |
hasDontEnumBug = !({toString:null}).propertyIsEnumerable('toString'), | |
dontEnums = [ | |
'toString', | |
'toLocaleString', | |
'valueOf', | |
'hasOwnProperty', | |
'isPrototypeOf', | |
'propertyIsEnumerable', | |
'constructor' | |
], | |
dontEnumsLength = dontEnums.length; | |
return function (obj) { | |
if (typeof obj !== 'object' && typeof obj !== 'function' || obj === null) throw new TypeError('Object.keys called on non-object') | |
var result = []; | |
for (var prop in obj) { | |
if (hasOwnProperty.call(obj, prop)) {result.push(prop);} | |
} | |
if (hasDontEnumBug) { | |
for (var i = 0; i < dontEnumsLength; i++) { | |
if (hasOwnProperty.call(obj, dontEnums[i])) { result.push(dontEnums[i])} | |
} | |
} | |
return result | |
} | |
})(); |
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