Question

Given an array a and two other int variables, k and temp, write a loop that reverses the elements of the array.

for (k = 0; k < a.length-1; k++) {
  temp = a[k];
  a[k] = a[a.length-1-k];
  a[a.length-1-k] = temp;
}

This is not working. Any idea why?

Answer 1

E.g., for a = [0, 1, 2, 3, 4, 5] you’ll switch 0 and 5 twice: when i == 0 and when i == 5. This double-switching will put both elements into their original positions: (0, 5) -> (5, 0) -> (0, 5).

Try to make your loop to go through half of array only: so each pair is switched once.