Constructor in Inheritance in OOP in PHP

When inheriting, you can override the parent's constructor. Let's look at an example. Suppose we have the following parent class:

<?php
	class User {
		private $name;
		private $surn;
		
		public function __construct($name, $surn) {
			$this->name = $name;
			$this->surn = $surn;
		}
		
		public function getName() {
			return $this->name;
		}
		public function getSurn() {
			return $this->surn;
		}
	}
?>

Suppose the following class inherits from the parent class:

<?php
	class Student extends User {
		
	}
?>

Suppose we want to extend the constructor in the child class by adding additional parameters to it:

<?php
	class Student extends User {
		private $year;
		
		public function __construct($name, $surn, $year) {
			
		}
	}
?>

In this case, we must call the parent constructor via parent::__construct() on the first line:

<?php
	class Student extends User {
		private $year;
		
		public function __construct($name, $surn, $year) {
			parent::__construct($name, $surn);
		}
	}
?>

The parent::__construct() command is essentially the parent's constructor. Therefore, let's pass the required parameters into it:

<?php
	class Student extends User {
		private $year;
		
		public function __construct($name, $surn, $year) {
			parent::__construct($name, $surn);
		}
	}
?>

Now, in the child class, let's record the year of study in the child's own property:

<?php
	class Student extends User {
		private $year;
		
		public function __construct($name, $surn, $year) {
			parent::__construct($name, $surn);
			$this->year = $year;
		}
	}
?>

Let's make a getter for the year of study:

<?php
	class Student extends User {
		private $year;
		
		public function __construct($name, $surn, $year) {
			parent::__construct($name, $surn);
			$this->year = $year;
		}
		
		public function getYear() {
			return $this->year;
		}
	}
?>

Let the Employee class inherit from the User class from this lesson.

Override the parent constructor in the Employee class, adding parameters for age and salary to it.

Make getters for age and salary.