Run results for: Map() vs Object() on write and read

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36

Browser: Chrome 122

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Map	97.5 Ops/sec
Object Iteration	8.9 Ops/sec

Script Preparation code:

function filter(v) {
  return v % 2
}

AخA
 
function filter(v) {  return v % 2}

Tests:

Map

const test = new Map()
for (var i=10000; i > 0; i--) {
  test.set(`key${i}`, i)
}

for (var i=100; i > 0; i--) {
  Array.from(test.values()).filter(filter)
}

​x
 
const test = new Map()for (var i=10000; i > 0; i--) {  test.set(`key${i}`, i)}​for (var i=100; i > 0; i--) {  Array.from(test.values()).filter(filter)}

Object Iteration

const test = {}
for (var i=10000; i > 0; i--) {
  test[`key${i}`] = i
}

for (var i=100; i > 0; i--) {
  const values = [];
  for (const id in test) {
    const value = test[id];
    if (filter(value)) {
      values.push(value);
    }
  }
}

 
const test = {}for (var i=10000; i > 0; i--) {  test[`key${i}`] = i}​for (var i=100; i > 0; i--) {  const values = [];  for (const id in test) {    const value = test[id];    if (filter(value)) {      values.push(value);    }  }}