Run results for: for-in vs object.keys (forEach) vs object.keys (for)

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.106 Safari/537.36

Browser: Chrome 91

Operating system: Linux

Device Platform: Desktop

Date tested: 3 years ago

Script Preparation code:

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

Tests:

for-in
for (var i=10000; i > 0; i--) { for (const key in obj) { // Do nothing } }
Object.keys for each
for (var i=10000; i > 0; i--) { Object.keys(obj).forEach((key) => { // Do nothing }); }
Object.keys for
for (var i=10000; i > 0; i--) { const keys = Object.keys(obj) for (let a = 0; a < keys.length; a++) { // Do nothing } }