Kisanja wakati wa urithi katika OOP katika PHP

Wakati wa urithi unaweza kubadilisha kisanja cha mzazi. Hebu tuangalie kwa mfano. Hebu tuchukulie tuna darasa la mzazi lifuatalo:

<?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;
		}
	}
?>

Hebu tuchukulie darasa lifuatalo linairithi kutoka kwa darasa la mzazi:

<?php
	class Student extends User {
		
	}
?>

Hebu tuchukulie tunataka katika darasa la mzao kupanua kisanja, tukiongeza vigezo vya ziada ndani yake:

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

Katika hali hii ni lazima mstari wa kwanza uitaje kisanja cha mzazi kupitia parent::__construct():

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

Amri parent::__construct() kimsingi ni kisanja cha mzazi. Kwa hivyo tupitishe parameta zinazohitajika ndani yake:

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

Sasa katika mzao mwaka wa masomo tuandike katika sifa yake mwenyewe ya mzao:

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

Tufanye getter kwa mwaka wa masomo:

<?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;
		}
	}
?>

Hebu tuchukulie darasa Employee linairithi kutoka kwa darasa User kutoka kwenye somo hili.

Badilisha katika darasa Employee kisanja cha mzazi, ukiongeza kigezo cha umri na mshahara.

Fanya getter kwa umri na mshahara.