function test() {
  const array = [];

  for (let i = 0; i < 10000000; i++) {
    array.push(Math.random());
  }

  console.time("For");
  for (let i = 0; i < array.length; i++) {
    array[i] * 10;
  }
  console.timeEnd("For");

  console.time("For of");
  for (let item of array) {
    item * 10;
  }
  console.timeEnd("For of");

  console.time("For each");
  array.forEach(item => {
    item * 10;
  });
  console.timeEnd("For each");
}

for (let i = 0; i < 10; i++) {
  test();
  console.log("--------");
}