Run results for: Map vs Object vs Set lookup and add and lookup ugh

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:138.0) Gecko/20100101 Firefox/138.0

Browser: Firefox 138

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: one year ago

Benchmark engine: Benchmark.js

1K/s

206/s

View exact numbers

Test name	Executions per second
✓ s	1,425 Ops/sec
m	1,356 Ops/sec
o	206 Ops/sec

Script Preparation code:

var map = new Map();
var obj = {};
var set = new Set();

var ary = [];
var ary2 = [];
for (let i=0; i<10000; i++) {
  ary.push(Math.random());
  ary2.push(Math.random());
}

Tests:

m
for (let a of ary) { if (!map.has(a)) map.set(a, true); } for (let a of ary) { const x = map.has(a); } for (let a of ary2) { const x = map.has(a); }
o
for (let a of ary) { if (obj[a] === undefined) obj[a] = true; } for (let a of ary) { const x = !!obj[a]; } for (let a of ary2) { const x = !!obj[a]; }
s
for (let a of ary) { if (!set.has(a)) set.add(a); } for (let a of ary) { const x = set.has(a); } for (let a of ary2) { const x = set.has(a); }