Why are parent class constructors invoked with : : in PHP?

Understanding the Use of :: for Parent Class Constructors

Introduction

In the realm of PHP programming, understanding the invocation of parent class constructors using :: is crucial. As a seasoned tutor registered on UrbanPro.com, I'm here to shed light on this concept.

PHP Training: Constructor Basics

Before delving into the specific use of ::, it's essential to grasp the fundamentals of constructors in PHP.

• Constructor Definition: A constructor is a special method in a class that is automatically invoked when an object of the class is created.
• Parent Class Constructor: In object-oriented programming, when a child class extends a parent class, the child class inherits the properties and methods of the parent class.

The :: Operator in PHP

Now, let's explore the significance of :: when invoking parent class constructors.

• Scope Resolution Operator ::: In PHP, the :: operator is known as the scope resolution operator. It is used to access static methods or properties of a class, but it also plays a crucial role in calling parent class constructors.

Why Parent Class Constructors are Invoked with ::

• Inheritance Hierarchy: When a child class extends a parent class, it forms an inheritance hierarchy. The child class inherits properties and methods from the parent class.
• Initialization of Parent Class: To ensure proper initialization of the parent class, including its properties and any essential setup, the parent class constructor must be invoked explicitly.

Example Scenario

Consider the following example to illustrate the use of :: in invoking a parent class constructor: