Run results for: Map. foreach

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36

Browser: Chrome 128

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 7 months ago

Test name	Executions per second
forEach	6.0 Ops/sec
Array	5.1 Ops/sec

Script Preparation code:

const originalMap = new Map(Array.from({ length: 1000000 }, (_, i) => [i, i]));

​x
 
const originalMap = new Map(Array.from({ length: 1000000 }, (_, i) => [i, i]));​

Tests:

forEach

const originalMap = new Map(Array.from({ length: 1000000 }, (_, i) => [i, i]));

const newMap = new Map();
  originalMap.forEach((value, key) => {
    newMap.set(key, value * 2);
  });
  return newMap;

 
const originalMap = new Map(Array.from({ length: 1000000 }, (_, i) => [i, i]));​const newMap = new Map();  originalMap.forEach((value, key) => {    newMap.set(key, value * 2);  });  return newMap;

Array

const originalMap = new Map(Array.from({ length: 1000000 }, (_, i) => [i, i]));

const newMap = new Map(
    Array.from(originalMap.entries(), ([key, value]) => [key, value * 2])
  );

 
const originalMap = new Map(Array.from({ length: 1000000 }, (_, i) => [i, i]));​const newMap = new Map(    Array.from(originalMap.entries(), ([key, value]) => [key, value * 2])  );