Object Oriented Programming

• CLASSES and objects – Two main aspects of object- oriented programming.
• A Class - is a template for object, and an Object is an instance of a class.
• two methods set_name() and get_name() for setting and getting the $name property.
• Objects of a class are created using the new keyword.
• Classes are nothing without objects! We can create multiple objects from a class. Each object has all the properties and methods defined in the class, but they will have different property values.
• In PHP, public, protected, and private are access modifiers that define the visibility of properties and methods in a class. These modifiers determine from where the properties and methods can be accessed.
• Public - Properties or methods declared as public can be accessed from outside the class, that is, they are visible everywhere, including outside the class and its subclasses.
• Protected - Properties or methods declared as protected are accessible within the class and its subclasses. They are not directly accessible from outside the class.
• Private - Properties or methods declared as private are only accessible within the class itself. They are not visible or accessible from outside the class, including its subclasses.
• Local Variable Scope - are declared within a function and can only be accessed within that function.
• Global Variable Scope - Global variables are declared outside of any function and can be accessed from any part of the script.
• Encapsulation - is one of the fundamental principles of Object-Oriented Programming (OOP) and involves bundling the data (attributes or properties) and methods (functions) that operate on the data into a single unit, which is called a class.
• Encapsulation - Additionally, it restricts direct access to some of the object's components and hides the internal details, exposing only what is necessary.
• encapsulation can be achieved using access modifiers such as public, protected, and private.
• Encapsulation - helps in maintaining a clear and consistent state of the object and provides a level of abstraction, making it easier to manage and modify the internal implementation without affecting the external code that uses the class.
• Object-Oriented Programming (OOP) - allows you to use classes and objects to organize your code in a more modular and reusable way.
• Inheritance - is a fundamental concept in OOP that allows a class (subclass or derived class) to inherit properties and methods from another class (superclass or base class).
• inheritance - is a mechanism that allows a new class (subclass or derived class) to inherit properties and behaviors from an existing class (superclass or base class)
• Inheritance - enables a subclass to use the attributes and methods of a superclass, allowing the subclass to specialize or extend the functionality of the superclass.
• Base Class (Superclass): The class whose properties and methods are inherited by another class is called the
• Derived Class (Subclass): The class that inherits properties and methods from another class is called .
• public: Inherited properties and methods are accessible from outside the subclass.
• protected: Inherited properties and methods are accessible within the subclass and its subclasses.
• private: Inherited properties and methods are not accessible in the subclass; only the public and protected members are inherited.
• polymorphism - is a concept that allows objects of different classes to be treated as objects of a common base class.
• Polymorphism enables a single interface to be used for a general set of actions, making it possible to work with objects of various types in a consistent manner.
• There are two main types of polymorphism in OOP: compile-time (or static) polymorphism and runtime (or dynamic) polymorphism.
• Compile-time (Static) Polymorphism Also known as method overloading or function overloading.
• Compile-time (Static) Polymorphism - Involves defining multiple methods in a class with the same name but different parameter lists.
• Runtime (Dynamic) Polymorphism Also known as method overriding.
• Runtime (Dynamic) Polymorphism - Involves creating a relationship between a base class and a derived class, where the derived class provides a specific implementation of a method declared in the base class.
• Polymorphism- can be achieved through both method overloading and method overriding.
• Method overriding - allowing a subclass to provide a specific implementation of a method defined in its parent class.
• Abstraction - involves creating abstract classes and methods that define a blueprint for other classes to follow.
• Abstraction - allows you to hide the implementation details and focus on the essential characteristics of an object.
• Abstraction - is achieved using abstract classes and abstract methods.
• Enumerate the Data types : STRING, FLOAT , BOOLEAN, ARRAY , NULL, RESOURCE , OBJECT, INTEGER.
• String - is a sequence of characters, like "Hello world!".
• String- can be any text inside quotes. You can use single or double quotes.
• Var_dump() - function returns the data type and value.