Run results for: Array.isArray

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.130 Safari/537.36

Browser: Chrome 79

Operating system: Windows

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
Array.isArray	245995.7 Ops/sec
isArray	285853.2 Ops/sec
instanceof	244828.4 Ops/sec

Script Preparation code:

var array = [1,3,5,7,9,20];
var value = "not an array";
var int8a = new Int8Array(6);

var isArray = Array.isArray;

function f1(v) {
  return Array.isArray(v);
}

function f2(v) {
  return isArray(v);
}

function f3(v) {
  return v instanceof Array;
}

Tests:

Array.isArray
if (!f1(array)) throw "error"; if (f1(value)) throw "error"; if (f1(int8a)) throw "error";
isArray
if (!f2(array)) throw "error"; if (f2(value)) throw "error"; if (f2(int8a)) throw "error";
instanceof
if (!f3(array)) throw "error"; if (f3(value)) throw "error"; if (f3(int8a)) throw "error";