Run results for: Sparse array vs Map for random access and iteration

Run details:

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Mobile Safari/537.36

Browser: Chrome Mobile 138

Operating system: Android

Device Platform: Mobile

Date tested: 11 months ago

Test name	Executions per second
Get from array (all hits)	710399.1 Ops/sec
Get from array (with misses)	404.2 Ops/sec
Get from map (all hits)	34145.6 Ops/sec
Get from map (with misses)	769762.8 Ops/sec
Iterate array	1720927.6 Ops/sec
Iterate map	1165826.1 Ops/sec

Script Preparation code:

window.indexes = [];
window.arr = [];
window.map = new Map();
for (let i = 0; i < 1000; i++) {
	if (Math.random() > 0.7) {
		window.indexes.push(i);
		window.arr[i] = true;
		window.map.set(i, true);
	}
}

Tests:

Get from array (all hits)
for (const idx of window.indexes) { const a = window.arr[idx]; }
Get from array (with misses)
for (let i = 0; i < 1000; i++) { const a = window.arr[i]; }
Get from map (all hits)
for (const idx of window.indexes) { const a = window.map.get(idx); }
Get from map (with misses)
for (let i = 0; i < 1000; i++) { const a = window.map.get(i); }
Iterate array
for (const val of window.arr) { const a = val; }
Iterate map
for (const val of window.map) { const a = val; }

Run results for: Sparse array vs Map for random access and iteration

Get from array (all hits)

Get from array (with misses)

Get from map (all hits)

Get from map (with misses)

Iterate array

Iterate map