Run results for: isArray

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 17_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/121.0.6167.66 Mobile/15E148 Safari/604.1

Browser: Chrome Mobile iOS 121

Operating system: iOS 17.3

Device Platform: Mobile

Date tested: 2 years ago

Benchmark engine: Benchmark.js

Array.isArray

21.2M/s

Object.prototype.toString

10.4M/s

[].constructor

9.0M/s

instanceof

8.8M/s

View exact numbers

Test name	Executions per second
✓ Array.isArray	21,184,454 Ops/sec
Object.prototype.toString	10,387,398 Ops/sec
[].constructor	8,971,009 Ops/sec
instanceof	8,790,013 Ops/sec

Script Preparation code:

var toStr = Object.prototype.toString
	
function toStrCase(obj){
  return toStr.call(obj) === '[object Array]'
}
function consCase(obj){
  return obj && obj.constructor === Array
}
function instCase(obj){
  return obj && obj instanceof Array
}
var isArray = Array.isArray

Tests:

Array.isArray
isArray([])
instanceof
instCase([])
[].constructor
consCase([])
Object.prototype.toString
toStrCase([])

Array.isArray vs Object.prototype.toString vs [].constructor vs instanceof

Array.isArray

instanceof

[].constructor

Object.prototype.toString