Run results for: For in vs For of

Run details:

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:66.0) Gecko/20100101 Firefox/66.0

Browser: Firefox 66

Operating system: Windows 7

Device Platform: Desktop

Date tested: 6 years ago

Test name	Executions per second
for in	5616.3 Ops/sec
for of	6045.4 Ops/sec

Script Preparation code:

var obj = {a: 1, b: 2, c: 3, d: 4}

AخA
 
var obj = {a: 1, b: 2, c: 3, d: 4}

Tests:

for in
for (var x in obj) { console.log(x); }
for (var x in obj) { console.log(x); }
for of
for (var x of Object.keys(obj)) { console.log(x); }
for (var x of Object.keys(obj)) { console.log(x); }