Benchmark: Object assign vs direct assignment by iterating keys without Object.keys

Object assign vs direct assignment by iterating keys without Object.keys (version: 0)

Tests:

With Object.assign()
var toSave = { "def":100101102, "ghi":null, "jkl":106107108, "mno":109110111.106107108, "pqr":'112113114', "stu":NaN, "vwx":118119120, "yz{":[ { "vwx":118119120 }, { "vwx":118119120 } ], }; var dest = { "abc":979899 }; if (toSave) { Object.assign(dest, toSave); }
With Iteration and Assignment
var toSave = { "def":100101102, "ghi":null, "jkl":106107108, "mno":109110111.106107108, "pqr":'112113114', "stu":NaN, "vwx":118119120, "yz{":[ { "vwx":118119120 }, { "vwx":118119120 } ], }; var dest = { "abc":979899 }; if (toSave) { var keys = Object.keys(dest); for (var i = 0; i < keys.length; i++) { dest[keys[i]] = toSave[keys[i]]; } }
With Iteration and .keys().forEach
var toSave = { "def":100101102, "ghi":null, "jkl":106107108, "mno":109110111.106107108, "pqr":'112113114', "stu":NaN, "vwx":118119120, "yz{":[ { "vwx":118119120 }, { "vwx":118119120 } ], }; var dest = { "abc":979899 }; if (toSave) { var keys = Object.keys(dest).forEach(key => { dest[key] = toSave[key]; }); }
With for iteration
var toSave = { "def":100101102, "ghi":null, "jkl":106107108, "mno":109110111.106107108, "pqr":'112113114', "stu":NaN, "vwx":118119120, "yz{":[ { "vwx":118119120 }, { "vwx":118119120 } ], }; var dest = { "abc":979899 }; if (toSave) { for (const key in toSave) { dest[key] = toSave[key]; } }

Rendered benchmark preparation results:

Previous results

Test case name	Result
With Object.assign()
With Iteration and Assignment
With Iteration and .keys().forEach
With for iteration

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Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36

Browser/OS: Chrome 122 on Mac OS X 10.15.7

Test name	Executions per second
With Object.assign()	2340598.0 Ops/sec
With Iteration and Assignment	4123526.0 Ops/sec
With Iteration and .keys().forEach	3499085.0 Ops/sec
With for iteration	2909476.0 Ops/sec