JS: Speed Comparison of Increment

By Xah Lee. Date: .

Speed Comparison of n = n + 1 vs n++

/*

bench.js
2022-07-10, 2022-08-27
comparing speed of n = n + 1 vs n++

*/

const f1 = ((x) => {
  let n = 1;
  for (let i = 1; i < x; i++) n = n + 1;
  return n;
});

const f2 = ((x) => {
  let n = 1;
  for (let i = 1; i < x; i++) n++;
  return n;
});

console.log(f1(10) === 10);
console.log(f2(10) === 10);

Deno.bench("normal assign", () => {
  f1(10_000);
});
Deno.bench("plus plus", () => {
  f2(10_000);
});
deno benchmark 2022-07-10 6FCy9
deno benchmark 2022-07-10

this means, n = n + 1 and n++ have the same speed.

JavaScript, Speed Comparison