Can someone explain this arrays output to me?

Question

int arr[ ] = new int[3];
for (int i = 0; i < 3; i++) {
arr[i] = i;
}
int res = arr[0] + arr[2];
System.out.println(res);

Answer 1

So the for loop isn't used? What is with the body of the for loop arr[i] = i; ?

Answer 2

Can you maybe try explain to me step by step, I still dont understand it.

Answer 3

I understand it, thank you so much!