Run results for: var is a non-empty array (v3)

Run details:

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/114.0

Browser: Firefox 114

Operating system: Ubuntu

Device Platform: Desktop

Date tested: 10 months ago

Test name	Executions per second
IsArray	68048780.0 Ops/sec
typecheck (nullable dot) (array)	60658060.0 Ops/sec
manual check cond	54119090.0 Ops/sec
typeof obj + length	60121330.0 Ops/sec
manual check with null-coalescing	46595430.0 Ops/sec

Script Preparation code:

var arr = [1,2,3];
var notArr = null;

Tests:

IsArray
const a = Array.isArray(arr) && arr.length > 0; const b = Array.isArray(notArr) && notArr.length > 0;
typecheck (nullable dot) (array)
const a = arr?.length > 0 && arr[0] !== undefined; const b = notArr?.length > 0 && notArr[0] !== undefined;
manual check cond
const a = arr !== null && arr !== undefined && arr.length > 0 && arr[0] !== undefined; const b = notArr !== null && notArr !== undefined && notArr.length > 0 && notArr[0] !== undefined;
typeof obj + length
const a = typeof arr === 'object' && arr !== null && arr.length > 0 && arr[0] !== undefined; const b = typeof notArr === 'object' && notArr !== null && notArr.length > 0 && notArr[0] !== undefined;
manual check with null-coalescing
const a = (arr ?? []).length > 0 && arr[0] !== undefined; const b = (notArr ?? []).length > 0 && notArr[0] !== undefined;