set_vs_array.js

const myset = new Set();
const myarray = [];

for (let i=0; i<1000 * 1000; i++) {
  myset.add(i);
  myarray.push(i);
}

function reportTime(label, callback) {
  const start = process.hrtime();

  callback();

  const precision = 3;
  const elapsed = process.hrtime(start)[1] / 1000000;
  console.log(process.hrtime(start)[0] + " s, " + elapsed.toFixed(precision) + " ms - " + label);
}


reportTime("Set#has()", () => {
  for (let i=0; i<1000 * 1000; i++) {
    const r = Math.floor(Math.random() * 1000 * 1000);
    myset.has(r);
  }
});

reportTime("Array#includes()", () => {
  for (let i=0; i<1000 * 1000; i++) {
    const r = Math.floor(Math.random() * 1000 * 1000);
    myarray.includes(r);
  }
});