Run results for: Summing an object

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.116 Safari/537.36

Browser: Chrome 53

Operating system: Windows

Device Platform: Other

Date tested: 8 years ago

Test name	Executions per second
For in	1958826.9 Ops/sec
Obj.keys for loop	1069902.5 Ops/sec
Object.keys reduce	758734.6 Ops/sec
For in function	7313833.5 Ops/sec
Object.keys for loop function	2324380.0 Ops/sec
Object.keys reduce function	1801651.2 Ops/sec
Object.keys for loop 2	356031.1 Ops/sec

Script Preparation code:

var obj = { "a": 1, "b": 2, "c": 3, "d": 4 };

Tests:

For in
var sum = 0; for (var val in obj) { sum += obj[val]; }
Obj.keys for loop
var sum = 0; var keys = Object.keys(obj); for (var i=0; i< keys.length; i++) { sum += obj[keys[i]]; }
Object.keys reduce
function add(sum, key) { return sum + obj[key]; } Object.keys(obj).reduce(add, 0);
For in function
function sumObj(obj) { var sum = 0; for (var val in obj) { sum += obj[val]; } return sum; } sumObj(obj);
Object.keys for loop function
function sumObj(obj) { var sum = 0; var keys = Object.keys(obj); for (var i=0; i< keys.length; i++) { sum += obj[keys[i]]; } return sum; } sumObj(obj);
Object.keys reduce function
function sumObj(obj) { function add(sum, key) { return sum + obj[key]; } return Object.keys(obj).reduce(add, 0); } sumObj(obj);
Object.keys for loop 2
function sumObj(obj) { var sum = 0; for (var i=0; i< Object.keys(obj).length; i++) { sum += obj[Object.keys(obj)[i]]; } return sum; } sumObj(obj);