Run results for: Set from Array vs Array#forEach(.add)

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/139.0.0.0 Safari/537.36

Browser: Chrome 139

Operating system: Windows

Device Platform: Desktop

Date tested: 8 months ago

Test name	Executions per second
new Set	10.2 Ops/sec
.add	7.7 Ops/sec
of	23.7 Ops/sec

Script Preparation code:

let sourceArray = []
for(let i=1; i<1000000; i++) {
 sourceArray.push(i) 
}

    class SetlikeArray extends Array {
       has(key) { return this.includes(key); }
       keys() { return this[Symbol.iterator]() }
       get size() { return this.length } 
    }

Tests:

new Set
const setObject = new Set(sourceArray)
.add
const setObject = new Set() sourceArray.forEach(x => setObject.add(x))
of
const setObject = new SetlikeArray(); for(let i=1; i<1000000; i++) { setObject.push(i) }

Run results for: Set from Array vs Array#forEach(.add)

new Set

.add

of