concat_bench.ts

// Install Deno: https://deno.land.
// Run with the command
// deno bench

const array1 = crypto.getRandomValues(new Uint8Array([1024 * 1024]));
const array2 = crypto.getRandomValues(new Uint8Array([1024 * 1024]));
const array3 = crypto.getRandomValues(new Uint8Array([1024 * 1024]));
const array4 = crypto.getRandomValues(new Uint8Array([1024 * 1024]));
const array5 = crypto.getRandomValues(new Uint8Array([1024 * 1024]));

Deno.bench("spread syntax", () => {
  const _ = new Uint8Array([
    ...array1,
    ...array2,
    ...array3,
    ...array4,
    ...array5,
  ]);
});

Deno.bench("push()", () => {
  const __ = [];
  for (const item of array1) {
    __.push(item);
  }
  for (const item of array2) {
    __.push(item);
  }
  for (const item of array3) {
    __.push(item);
  }
  for (const item of array4) {
    __.push(item);
  }
  for (const item of array5) {
    __.push(item);
  }
  const _ = new Uint8Array(__);
});