There are 4 ways of array iteration:

// 1: for

for (let i = 0; i < arr.length; ++i) {
  console.log(arr[i]);
}

// 2: forEach

arr.forEach((v, i) => console.log(v));

// 3: for in

for (let i in arr) {
  console.log(arr[i]);
}

// 4: for of

for (const v of arr) {
  console.log(v);
}

Summary: 1 and 3 solutions create extra variable, 2 - create extra function context. The best way is 4th - "for of".

There are 4 ways of array iteration:

// 1: for

for (let i = 0; i < arr.length; ++i) {
  console.log(arr[i]);
}

// 2: forEach

arr.forEach((v, i) => console.log(v));

// 3: for in

for (let i in arr) {
  console.log(arr[i]);
}

// 4: for of

for (const v of arr) {
  console.log(v);
}

Summary: 1 and 3 solutions create extra variable, 2 - create extra function context. The best way is 4th - "for of".