How does this code produce an IndexOutOfBoundsException?

Question

int arr[] = new int[5];
for(int i = 0; i <= 5; ++i)
arr[i] = i;

Answer 1

An array of size 5:
[0] = 1st element
[1] = 2nd element
[2] = 3rd element
[3] = 4th element
[4] = 5th element

so trying to call [5] would be attempting to retrieve the 6th element in an array with a size of 5, which is an IndexOutOfBounds. Your for loop condition should read i<5