string and int on parameters. Return types after :.

Goal

Echo a typed total.

<?php
function total(int $units, int $price): int {
  return $units * $price;
}
echo total(12, 40), PHP_EOL;

<?php
function greet(string $name): string {
  return "Hello, " . $name;
}
echo greet("Mombasa"), PHP_EOL;

<?php
function busy(int $units): bool {
  return $units >= 10;
}
echo busy(12) ? "yes" : "no", PHP_EOL;

<?php
$units = 8;
echo gettype($units), PHP_EOL;