Run results for: Map() vs Object() + Reduce vs Iteration

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.2 Safari/605.1.15

Browser: Safari 17

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

Map

568/s

Object Iteration

221/s

View exact numbers

Test name	Executions per second
✓ Map	568 Ops/sec
Object Iteration	221 Ops/sec

Script Preparation code:

var obj = {
  'a': {
    id: 'a',
    num: 1
  },
  'b': {
    id: 'b',
    num: 1
  },
  'c': {
    id: 'c',
    num: 1
  },
  'd': {
    id: 'd',
    num: 1
  },
  'e': {
    id: 'e',
    num: 1
  },
  'f': {
    id: 'f',
    num: 1
  },
  'g': {
    id: 'g',
    num: 1
  },
};
var objmap = new Map(Object.entries(obj))
function callback(acc, value) {
  return acc + value.num
}

Tests:

Map
for (var i=10000; i > 0; i--) { Array.from(objmap.values()).reduce(callback, 0); }
Object Iteration
for (var i=10000; i > 0; i--) { let index = 0; let result = 0; for (const id in obj) { const value = obj[id]; result = callback(result, value, index); index += 1; } }