As a short diversion from arrays, you will by now have been using the arithmetic operators +, -, *, / and % enough to appreciate the usefulness of the composite operators. These are +=, -=, *=, /= and %=, and their uses are:
x += y // shorthand for x = x + y x -= y // shorthand for x = x - y x *= y // shorthand for x = x * y x /= y // shorthand for x = x / y x %= y // shorthand for x = x % y