Run results for: for-in vs Object.keys benchmark 3

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.69 Safari/537.36

Browser: Chrome 95

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
for-in	122.3 Ops/sec
Object.keys with forEach	125.8 Ops/sec
Object.keys with reduce	133.5 Ops/sec
Object.keys with for-of	133.2 Ops/sec
for-in with hasOwnProperty	54.1 Ops/sec

Script Preparation code:

var codes = Array.from(Array(26)).map((_, i) => i + 65);
var alphabet = codes.reduce((acc, code) => {
  acc[String.fromCharCode(code)] = code;

  return acc;
}, {});

Tests:

for-in
for (var i=1000; i > 0; i--) { var result = {}; for (var key in alphabet) { result[key] = alphabet[key]; } };
Object.keys with forEach
for (var i=1000; i > 0; i--) { var result = {}; Object.keys(alphabet).forEach(key => { result[key] = alphabet[key]; }); };
Object.keys with reduce
for (var i=1000; i > 0; i--) { var result = Object.keys(alphabet).reduce((acc, key) => { acc[key] = alphabet[key]; return acc; }, {}); };
Object.keys with for-of
for (var i=1000; i > 0; i--) { var result = {}; for (var key of Object.keys(alphabet)) { result[key] = alphabet[key]; } };
for-in with hasOwnProperty
for (var i=1000; i > 0; i--) { var result = {}; for (var key in alphabet) { if (Object.prototype.hasOwnProperty.call(alphabet, key)) { result[key] = alphabet[key]; } } };

Run results for: for-in vs Object.keys benchmark 3

for-in

Object.keys with forEach

Object.keys with reduce

Object.keys with for-of

for-in with hasOwnProperty