Could you explain this code for me

Question

let arr = [1, 2, 3];
for (let k = 0; k < arr.length; k++) {
console.log(arr[k]);
}

//Output is
1
2
3
//why is the output like this 123

Answer 1

The variable k will be 0, then 1, then 2. Computers start counting at 0, so to access the first element of the array we have to use the index 0 (arr[0] is 1). So then we print the second element (index 1) and the third (index 2).