Run results for: ES6 Map Merge vs forEach

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 17_4 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/125.0.6422.51 Mobile/15E148 Safari/604.1

Browser: Chrome Mobile iOS 125

Operating system: iOS 17.4

Device Platform: Mobile

Date tested: 6 months ago

Test name	Executions per second
Merge	8204.0 Ops/sec
Loop	14333.1 Ops/sec

Script Preparation code:

const entries1 = [];
const entries2 = [];
for (let i = 0; i < 1000; i++) {
  entries1[i] = [i , i];
}
for (let i = 0; i < 1000; i++) {
  entries2[i] = [i + 500, i + 600];
}
const pathSegmentMap = new Map(entries1);
const newSegmentMap = new Map(entries2);

Tests:

Merge
const entries1 = []; const entries2 = []; for (let i = 0; i < 1000; i++) { entries1[i] = [i , i]; } for (let i = 0; i < 1000; i++) { entries2[i] = [i + 500, i + 600]; } const pathSegmentMap = new Map(entries1); const newSegmentMap = new Map(entries2); const mergeMap = new Map([...pathSegmentMap, ...newSegmentMap]);
Loop
const entries1 = []; const entries2 = []; for (let i = 0; i < 1000; i++) { entries1[i] = [i , i]; } for (let i = 0; i < 1000; i++) { entries2[i] = [i + 500, i + 600]; } const pathSegmentMap = new Map(entries1); const newSegmentMap = new Map(entries2); newSegmentMap.forEach((value, key) => { pathSegmentMap.set(key, value); });

Run results for: ES6 Map Merge vs forEach

Merge

Loop