Run results for: is object with keys

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36 Edg/122.0.0.0

Browser: Chrome 122

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
for in	15161.9 Ops/sec
Object.keys	20370.5 Ops/sec

Script Preparation code:

var obj_empty = {};
var obj_sm = {};
var obj_md = {};
var obj_lg = {};
var obj_xl = {};

for (let i=0; i<10000; i++) {
	if (i<10) obj_sm[Math.random()] = Math.random();
  	if (i<50) obj_md[Math.random()] = Math.random();
  	if (i<1000) obj_lg[Math.random()] = Math.random();
  	obj_xl[Math.random()] = Math.random();
}

var isObject = val => !!val && typeof val === 'object' && val.constructor === Object;

Tests:

for in
const forIn = (o) => { if (!isObject(o)) return false; for (const k in o) if (o.hasOwnProperty(k)) return false; return true; } console.log(forIn(obj_empty)); console.log(forIn(obj_sm)); console.log(forIn(obj_md));
Object.keys
const keys = (o) => isObject(o) && Object.keys(o).length > 0; console.log(keys(obj_empty)); console.log(keys(obj_sm)); console.log(keys(obj_md));

Run results for: is object with keys

for in

Object.keys