Run results for: object key vs indexof

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:82.0) Gecko/20100101 Firefox/82.0

Browser: Firefox 82

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
loop lookup	843692.2 Ops/sec
array indexed	72010608.0 Ops/sec
key lookup	174807968.0 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];

Run results for: object key vs indexof

loop lookup

array indexed

key lookup