Run results for: Object.keys vs _Object.keys vs Object_keys

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; rv:11.0) like Gecko

Browser: IE 11

Operating system: Windows

Device Platform: Other

Date tested: 7 years ago

Test name	Executions per second
Object.keys	1568.3 Ops/sec
_Object.keys	1946.7 Ops/sec
Object_keys	1626.0 Ops/sec
ObjectLocal	1947.6 Ops/sec

Script Preparation code:

var _Object = Object;
var Object_keys = Object.keys;
var Object_getOwnPropertyDescriptor = Object.getOwnPropertyDescriptor;

var testCases = [];
for (var i = 0; i < 1000; i++) {
    testCases.push({ id: i });
}
var Test = (function () {
    function Test() {
    }
    Test.prototype.test1 = function () {
        for (var i = 0, len = testCases.length; i < len; i++) {
          	var testCase = testCases[i];
            Object.keys(testCase);
            Object.getOwnPropertyDescriptor(testCase, "id")
        }
    };
    Test.prototype.test2 = function () {
        for (var i = 0, len = testCases.length; i < len; i++) {
          	var testCase = testCases[i];
            _Object.keys(testCase);
            _Object.getOwnPropertyDescriptor(testCase, "id")
        }
    };
    Test.prototype.test3 = function () {
        for (var i = 0, len = testCases.length; i < len; i++) {
          	var testCase = testCases[i];
            Object_keys(testCase);
            Object_getOwnPropertyDescriptor(testCase, "id")
        }
    };
      Test.prototype.test4 = function () {
        var ObjectLocal = Object;
        for (var i = 0, len = testCases.length; i < len; i++) {
          	var testCase = testCases[i];
            ObjectLocal.keys(testCase);
            ObjectLocal.getOwnPropertyDescriptor(testCase, "id")
        }
    };
    return Test;
}());

Tests:

Object.keys
(new Test()).test1()
_Object.keys
(new Test()).test2()
Object_keys
(new Test()).test3()
ObjectLocal
(new Test()).test4()