PHP OOP Test

 class Animal {
 private int $itsAge;
 public function Animal($startAge) { $this->$itsAge = $startAge; }
 public function getAge() { return $this->$itsAge; }
 }
 $bear = new Animal(5);
 print "Our bear is ".$bear->getAge()." years old.";

Fatal error: Cannot access empty property in /home/ajh/demo/php-tests/php-oop.php on line 14