Vitu ndani ya Madarasa katika OOP katika PHP

Katika madarasa unaweza kutumia vitu vya madarasa mengine. Hebu tuangalie kwa mfano. Tuseme tunataka kutengeneza mtumiaji aina ya jina na jina la ukoo, pamoja na jiji, ambalo anaishi. Tuseme tuna darasa lifuatalo kwa jiji:

php<?php
  class City {
    public $name;
    
    public function __construct($name) {
      $this->name = $name;
    }
  }
?>

Tutapeana jina, jina la ukoo na jiji kama vigezo vya mjenzi:

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

Wakati huu jina na jina la ukoo watakuwa nyuzi, lakini jiji - kitu cha darasa lake la pekee:

php<?php
  $city = new City('luis');
  $user = new User('john', 'smit', $city);
?>

Wacha tuonyeshe jina la mtumiaji wetu:

php<?php
  echo $user->name;
?>

Sasa hebu tuonyeshe jina la jiji kwa mtumiaji wetu:

php<?php
  echo $user->city->name;
?>

php<?php
  class Employee {
    public $name;
    public $position;
    public $department;
  
    public function __construct($name, $position, $department) {
      $this->name = $name;
      $this->position = $position;
      $this->department = $department;
    }
  }
?>