PHP da OOP da Klass Ichidagi Statik Usullar

Agar siz klass ichida statik usullardan foydalanmoqchi bo'lsangiz, ularga $this-> orqali emas, balki self:: yordamida murojaat qilishingiz kerak.

Misol sifatida, bizning Math klassimizga sonlarning ikki baravar yig'indisini topadigan getDoubleSum usulini qo'shamiz. Yangi usul ichida allaqachon mavjud bo'lgan getSum usulidan foydalanamiz:

<?php
	class Math
	{
		// Ikki baravar yig'indini topamiz:
		public static function getDoubleSum($a, $b)
		{
			return 2 * self::getSum($a, $b); // boshqa usuldan foydalanamiz
		}
		
		public static function getSum($a, $b)
		{
			return $a + $b;
		}
		
		public static function getProduct($a, $b)
		{
			return $a * $b;
		}
	}
?>

Yangi usuldan foydalanamiz:

<?php
	echo Math::getDoubleSum(1, 2);
?>

Quyidagi klassning usullarini statik usullarga o'zgartiring:

<?php
	class ArraySumHelper
	{
		public function getSum1($arr)
		{
			return $this->getSum($arr, 1);
		}
		
		public function getSum2($arr)
		{
			return $this->getSum($arr, 2);
		}
		
		public function getSum3($arr)
		{
			return $this->getSum($arr, 3);
		}
		
		public function getSum4($arr)
		{
			return $this->getSum($arr, 4);
		}
		
		private function getSum($arr, $power) {
			$sum = 0;
			
			foreach ($arr as $elem) {
				$sum += pow($elem, $power);
			}
			
			return $sum;
		}
	}
?>