Factory pattern in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the Factory pattern in PHP?

The Factory pattern is a design pattern that creates objects without exposing the creation logic to the client. It provides a method to create objects based on input or conditions, helping to keep code flexible and easy to maintain.

beginner

Why use the Factory pattern instead of creating objects directly?

Using the Factory pattern helps separate object creation from usage. This makes code easier to change, test, and extend because the client code does not depend on specific classes but on interfaces or abstract classes.

intermediate

In the Factory pattern, what role does the factory class play?

The factory class contains a method that decides which class to instantiate and returns the created object. It hides the details of object creation from the client.

beginner

What is a simple example of a Factory pattern in PHP?

A simple example is a ShapeFactory class with a method createShape($type) that returns a Circle, Square, or Triangle object based on the $type parameter. The client calls createShape without knowing the details of each shape class.

intermediate

How does the Factory pattern improve code maintenance?

It centralizes object creation in one place. When you add new types or change creation logic, you only update the factory, not all client code. This reduces errors and makes the system easier to extend.

What does the Factory pattern mainly help with?

A Handling user input validation

B Improving database queries

C Styling HTML elements

D Creating objects without exposing creation logic

The Factory pattern focuses on creating objects while hiding the creation details from the client.

In PHP, where is the object creation logic placed in the Factory pattern?

A In the database

B Inside the factory class

C In the client code

D In the HTML template

The factory class contains the logic to decide which object to create and returns it.

Which of these is a benefit of using the Factory pattern?

A Easier to change object creation without affecting client code

B Faster execution of SQL queries

C Better CSS styling

D Simplifies user authentication

The Factory pattern allows changing object creation in one place without modifying client code.

What would a factory method typically return?

A A CSS stylesheet

B A string of HTML

C An object instance

D A database connection

The factory method returns an instance of a class based on input or conditions.

Which design principle does the Factory pattern support?

A Encapsulation of object creation

B Direct manipulation of global variables

C Hardcoding class names in client code

D Mixing UI and business logic

The Factory pattern encapsulates object creation, hiding it from the client.

Explain the Factory pattern and why it is useful in PHP programming.

Think about how you can create objects without the client knowing the details.

Describe a simple example of implementing the Factory pattern in PHP.

Imagine a shape factory that creates different shapes based on input.