declare(strict_types=1);
function greet(string $name = "Guest"): string {
return "Hello, $name";
}
echo greet() . "\n"; // OK
echo greet("Sam Sung") . "\n"; // OK
echo greet(123); // TypeError
/*
run:
ERROR!
Hello, Guest
Hello, Sam Sung
Fatal error: Uncaught TypeError: greet(): Argument #1 ($name) must be of type string, int given
*/