From version 5, PHP introduced **object oriented programming**, otherwise known as **OOP**. Because of OOP, today we can say that PHP is a fully-featured language capable of building a lot of applications.  

In this shot, by mentions of OOP, we are referring to the use of classes. A **class** is a piece of code that identifies an abstract concept. 
 
Inside a class, we have:
- Variables, which are called **properties**.
- Functions, which are called **methods**.

Let's look at a visual representation of a class.

##   
### Example 
We can define a class with the keyword `class`. After writing the name of the class, we can define our methods and properties. Both can have visibility: `public`, `private`, and `protected`. A class needs to be initialized with the `new` keyword.

Let's look at an example.

<?php 

class MyHello {
  private $sampleHello;
  public function __construct(){
    $this->sampleHello = "Hello, educative!";
  }
  public function sayHello(){
    echo $this->sampleHello;
  }
}

$instance = new MyHello(); // inizialize a class
$instance->sayHello(); // call a method

### Explanation
In the code above, we have constructed a class named `MyHello`. The class has one `private` property called `$sampleHello` and two `public` properties called the `__construct()` (the constructor of the class) and `sayHello()`. 

In line 13, a new instance of the class is created using the `new` keyword. Then in line 14, the `sayHello()` method is invoked of the previously created instance.

How to make a class in PHP

Example

Explanation