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<?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<?php
  class Student extends User {
    
  }
?>

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

php<?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<?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<?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<?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<?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;
    }
  }
?>