Run results for: object key vs indexof

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

Browser: Chrome 122

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

key lookup

7.7M/s

array indexed

3.9M/s

loop lookup

2.3M/s

View exact numbers

Test name	Executions per second
✓ key lookup	7,734,552 Ops/sec
array indexed	3,908,394 Ops/sec
loop lookup	2,279,662 Ops/sec

Script Preparation code:

var a = [{"id":7,"h":76},{"id":4,"h":34},{"id":9,"h":89}];
var b = [];
for(var i=0;i<a.length;i++)b[i] = a[i].id;
var c = [];
for(var i=0;i<a.length;i++)c[a[i].id] = a[i];

Tests:

loop lookup
for(var i in a)if(i.id==9)return i;
array indexed
return a[b.indexOf(9)];
key lookup
return c[9];