Static Properties Inside a Class in OOP in PHP

You can access static properties inside the class itself using self::. See the example:

<?php
	class Test
	{
		// Private static property:
		private static $property;
		
		// Static method for setting the property value:
		public static function setProperty($value)
		{
			self::$property = $value; // write data to our static property
		}
		
		// Static method for getting the property value:
		public static function getProperty()
		{
			return self::$property; // read the recorded data
		}
	}
?>

Let's use our class:

<?php
	Test::setProperty('test'); // write data to the property
	echo Test::getProperty();  // output to the screen
?>

Create a class Num that will have two private static properties: num1 and num2. Let the property num1 store the number 2 by default, and the property num2 store the number 3.

Create a method getSum in the class Num, which will output the sum of the values of the properties num1 and num2 to the screen.