Run results for: real for-in vs object.keys

Run details:

User agent: Mozilla/5.0 (Linux; Android 11; SM-N975U) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.104 Mobile Safari/537.36

Browser: Chrome Mobile 96

Operating system: Android

Device Platform: Mobile

Date tested: 3 years ago

Test name	Executions per second
for-in	5.3 Ops/sec
Object.keys	1.9 Ops/sec

Script Preparation code:

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

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

Tests:

let c=0;
for (var i=1000000; i > 0; i--) {
  for (var key in obj) {
      c++;
  }
}

 
let c=0;for (var i=1000000; i > 0; i--) {  for (var key in obj) {      c++;  }}

let c=0;
for (var i=1000000; i > 0; i--) {
  let list=Object.keys(obj);
  let l=list.length;
  for(let ii=0;ii<l;ii++){
	c++;
  }
}

 
let c=0;for (var i=1000000; i > 0; i--) {  let list=Object.keys(obj);  let l=list.length;  for(let ii=0;ii<l;ii++){    c++;  }}