Inheritance from a Class and Implementation of an Interface in OOP in PHP

A class can inherit from another class and at the same time implement some interface. Let's consider a practical example.

Suppose we want to create a class Programmer, which will have a name, salary, and a list of languages that the programmer knows. Our class description is rather vague so far: yes, the class will have a name, salary, languages - but what methods will our class have?

Let's describe our class more accurately using the interface iProgrammer:

<?php
	interface iProgrammer
	{
		public function __construct($name, $salary);
		public function getName();
		public function getSalary();
		public function getLangs();
		public function addLang($lang);
	}
?>

Suppose we dug into our already implemented classes and, it turns out, we already have a similar class Employee. It does not implement all the methods of the Programmer class, but some. Here is the code of our existing class:

<?php
	class Employee
	{
		private $name;
		private $salary;
		
		public function __construct($name, $salary)
		{
			$this->name = $name;
			$this->salary = $salary;
		}
		
		public function getName()
		{
			return $this->name;
		}
		
		public function getSalary()
		{
			return $this->salary;
		}
	}
?>

It is logical in our case to make it so that our new class Programmer inherits some of the methods it needs from the class Employee (and we will implement the rest later in the new class itself):

<?php
	class Programmer extends Employee
	{
		
	}
?>

At the same time, we know that the Pogrammer class should implement the interface iProgrammer:

<?php
	class Programmer implements iProgrammer
	{
		
	}
?>

Let's combine inheritance from the class Employee and implementation of the interface iProgrammer:

<?php
	class Programmer extends Employee implements iProgrammer
	{
		
	}
?>

It turns out that our Pogrammer class will inherit from the Employee class the methods __construct, getName and getSalary, and the methods addLang and getLangs we will have to implement ourselves:

<?php
	class Programmer extends Employee implements iProgrammer
	{
		public function addLang($lang)
		{
			// implementation
		}
		
		public function getLangs()
		{
			// implementation
		}
	}
?>

The iProgrammer interface doesn't care whether the methods are native to the class or inherited - the main thing is that all the described methods are implemented.

Copy the code of my Employee class and the code of the iProgrammer interface. Do not copy my template of the Programmer class - without looking at my code, implement this class yourself.