Array vs Set lookup benchmark

array-set-perf.js

function bench(cb, arg, label) {
  console.time(label)
  cb(arg)
  console.timeEnd(label)
}

function createArray(length) {
  return Array.from({ length }, (_, i) => i)
}

function nestedSetSearch(array) {
  const set = new Set(array)
  return array.filter(item => set.has(item))
}

function nestedArraySearch(array) {
  return array.filter(item => array.includes(item))
}

const arrayLengths = [100, 1_000, 10_000, 100_000]

function run() {
  arrayLengths.forEach(length => {
    bench(nestedArraySearch, createArray(length), `array ${length}`.padEnd(14))
  })
  arrayLengths.forEach(length => {
    bench(nestedSetSearch, createArray(length), `set ${length}`.padEnd(14))
  })
}

run()

/*
MacBook Air 2020, Chrome 108
array 100     : 0.056884765625 ms
array 1000    : 0.280029296875 ms
array 10000   : 15.889892578125 ms
array 100000  : 543.7998046875 ms
set 100       : 0.045166015625 ms
set 1000      : 0.087158203125 ms
set 10000     : 0.864990234375 ms
set 100000    : 8.87109375 ms
*/