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

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.36

Browser: Chrome 107

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
Get from array (all hits)	37519.4 Ops/sec
Get from array (with misses)	11229.0 Ops/sec
Get from map (all hits)	37396.1 Ops/sec
Get from map (with misses)	9129.9 Ops/sec
Iterate array	1372793.8 Ops/sec
Iterate map	1249797.0 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