Calling Methods Inside Classes in OOP in PHP

Some methods can be called inside others via $this. Let's look at an example. Suppose we have a class with a user and a method that returns a property:

<?php
	class User {
		public $name;
		
		public function show() {
			return $this->name;
		}
	}
?>

Suppose we also have a method cape, which converts the first letter of a string to uppercase:

<?php
	class User {
		public $name;
		
		public function show() {
			return $this->name;
		}
		
		public function cape($str) {
			return mb_strtoupper(mb_substr($str, 0, 1)) . mb_substr($str, 1);
		}
	}
?>

Let's use the method cape inside the method show:

<?php
	class User {
		public $name;
		
		public function show() {
			return $this->cape($this->name);
		}
		
		public function cape($str) {
			return mb_strtoupper(mb_substr($str, 0, 1)) . mb_substr($str, 1);
		}
	}
?>

Make a class Student with properties name and surn.

Make a helper method, which will get the first character of a string and make it uppercase.

Make a method that will return the student's initials, that is, the first letters of their first name and last name.