Run results for: Map vs Object 123

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36

Browser: Chrome 69

Operating system: Mac OS X 10.10.5

Device Platform: Desktop

Date tested: 5 years ago

Test name	Executions per second
Map lookup	419.6 Ops/sec
Obj lookup	76.4 Ops/sec

Script Preparation code:

const map = new Map();
const obj = {};

const count = 100
const l = []

for (let x=0; x<=count; x++) {
  l.push([[''+x, x]])
}

function bMap() {
  'use strict'
  for (let j = 0; i+j < count; j++){
    for (let i = 0; i < count; i++) {
      const [k, v] = l[i]
      const n = map.get(k)
      if (n !== undefined) {
          map.set(k, v)
      } else {
          map.set(k, v+j)
      }
    }
  }
}

function bObj() {
  'use strict'
  for (let j = 0; i+j < count; j++){
    for (let i = 0; i < count; i++) {
      const [k, v] = l[i]
      const n = obj[k]
      if (n !== undefined) {
          obj[k] = v
      } else {
          obj[k] = v+j
      }
    }
  }
}

Tests:

Map lookup
bMap()
Obj lookup
bObj()

Run results for: Map vs Object 123

Lookup of map vs object

Map lookup

Obj lookup