PHP-de OOP miras alanda guruplaýjy

Miras alanda, atanyň guruplaýjysynyň üstüni özgerdip bolýar. Mysal üçin seredeliň. Aşakdaky ýaly ata klasymyz bolsun:

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;
    }
  }
?>

Ata klasdan aşakdaky klas miras alsyn:

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

Farz edeliň, miras alyjy klasda guruplaýjyny giňeltmek isleýäris, ona goşmaça parametrler goşup:

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

Bu ýagdaýda, ilkinji setir hökmünde ata guruplaýjyny parent::__construct() arkaly çagyrmaly:

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

parent::__construct() buýrugy esasan atanyň guruplaýjysydyr. Şonuň üçin ony talap edilýän parametrler bilen üpjün edeliň:

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

Indi miras alyjyda okuw ýyllygyny miras alyjynyň öz aýratynlygyna ýazalyň:

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

Okuw ýyly üçin getter döredeliň:

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;
    }
  }
?>