Multiple interface implementation in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is multiple interface implementation in PHP?

It means a class can use more than one interface at the same time, promising to provide all methods those interfaces require.

beginner

How do you declare a class that implements two interfaces named A and B in PHP?

Use the syntax: <code>class MyClass implements A, B { }</code> where MyClass must define all methods from both A and B.

intermediate

Why use multiple interface implementation?

It helps organize code by separating different behaviors into interfaces, letting a class combine them as needed.

intermediate

What happens if a class does not implement all methods from multiple interfaces it declares?

PHP will throw a fatal error because the class must provide all methods declared in every interface it implements.

advanced

Can interfaces extend other interfaces in PHP?

Yes, interfaces can extend one or more interfaces, allowing a child interface to inherit all methods from its parents.

How do you implement multiple interfaces in a PHP class?

A Use a semicolon-separated list after the class name

B Use multiple extends keywords

C Use the new keyword multiple times

D Use a comma-separated list after the implements keyword

In PHP, you list interfaces separated by commas after the implements keyword.

What must a class do when it implements multiple interfaces?

A Define no methods

B Define all methods from all interfaces

C Define methods from only one interface

D Only define methods it wants

The class must provide all methods declared in every interface it implements.

Which keyword is used to declare an interface in PHP?

A implements

B class

C interface

D extends

The keyword 'interface' is used to declare an interface.

Can a PHP interface extend multiple interfaces?

A Yes

B No

C Only one interface

D Only classes can extend multiple interfaces

Interfaces in PHP can extend multiple interfaces.

What error occurs if a class misses a method from an implemented interface?

A Fatal error

B Warning

C Notice

D No error

PHP throws a fatal error if a class does not implement all interface methods.

Explain how multiple interface implementation works in PHP and why it is useful.

Think about how a class promises to do many things by following multiple contracts.

Describe the syntax and rules for a PHP class implementing two interfaces named Logger and Formatter.

Focus on the implements keyword and method requirements.