PHP da OOP da Meros olishda Konstruktor

Meros olish paytida ota-ona konstruktorini qayta belgilash mumkin. Keling, buni misol orgali ko'ramiz. Faraz qilaylik, bizda quyidagi ota-ona klass mavjud:

<?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;
		}
	}
?>

Faraz qilaylik, ota-ona klasidan quyidagi klass meros oladi:

<?php
	class Student extends User {
		
	}
?>

Faraz qilaylik, biz voris klassda konstruktorni kengaytirmoqchimiz, unga qo'shimcha parametrlar qo'shish orqali:

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

Bunday holatda biz birinchi qator sifatida parent::__construct() orqali ota-ona konstruktorini chaqirishimiz shart:

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

parent::__construct() buyrug'i aslida ota-ona konstruktoridir. Shuning uchun unga talab qilinadigan parametrlarni uzatamiz:

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

Endi vorisda o'quv yilini vorisning o'z xususiyatiga yozamiz:

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

O'quv yili uchun getter yaratamiz:

<?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;
		}
	}
?>

Faraz qilaylik, Employee klassi ushbu darsdagi User klasidan meros oladi.

Employee klasida ota-ona konstruktorini qayta belgilang, unga yosh va maosh parametrlarini qo'shing.

Yosh va maosh uchun getterlarni yarating.