Run results for: for-in-hasOwnProperty vs object.keys-direct

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 15_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.0 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 15

Operating system: iOS 15.0

Device Platform: Mobile

Date tested: 2 years ago

Script Preparation code:

var obj = {
  'a': 1,
  'b': 1,
  'c': 1,
  'd': 1,
  'e': 1,
  'f': 1,
  'g': 1
};

Tests:

for-in-hasOwnProperty
for (var i=10000; i > 0; i--) { for (var key in obj) { if(obj.hasOwnProperty(key)) { console.log(key); } } }
Object.keys-direct
for (var i=10000; i > 0; i--) { var keys = Object.keys(obj); for(var j = 0, l = keys.length; j < l; j++) { console.log(keys[j]); } }
Object.keys
for (var i=10000; i > 0; i--) { Object.keys(obj).forEach(key => console.log(key)); }
for-in
for (var i=10000; i > 0; i--) { for (var key in obj) { console.log(key); } }