Functions in PHP

Functions let you reuse code instead of repeating it.

Simple function

function greet() {
  echo "Hello!";
}

greet();

With parameters

function greetUser($name) {
  return "Hello $name";
}

echo greetUser("Daniel");

Default values

function greetUser($name = "Guest") {
  return "Hello $name";
}

Type hints (modern PHP)

function add(int $a, int $b): int {
  return $a + $b;
}

Next: Variable scope and global variables.