Let's test the access modifiers we learned earlier.
protected can also be used in declared classes, and can also be used in inherited child classes.
- <?php
- class parents
- {
- protected $parents = "Parental car";
- }
- class child extends parents
- {
- public function rentCar()
- {
- return "Borrow a {$this->parents}";
- }
- }
- $test = new child;
- echo $test->rentCar();
- ?>
Result of the code above
The above code declared a property as protected in the parent class. So you could use that property in a child class.
This time, I'll change protected to private in the same code.
Then, of course, it is a property that can only be used in a parent class, so it cannot be used in a child class.
- <?php
- class parents
- {
- private $parents = "Parental car";
- }
- class child extends parents
- {
- public function rentCar()
- {
- if(isset($this->parents)){
- return "Borrow a {$this->parents}";
- } else {
- return "I can't rent a car.";
- }
- }
- }
- $test = new child;
- echo $test->rentCar();
- ?>
Result of the code above
The isset function determines whether the variable is present and returns true if it exists and false if it does not exist.