Enums in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an enum in PHP?

An enum in PHP is a special type that lets you define a set of named values. It helps group related constants together, making code easier to read and safer.

beginner

How do you define a basic enum in PHP?

Use the enum keyword followed by the enum name and a list of cases inside curly braces. For example:<br>

enum Status { case Pending; case Approved; case Rejected; }

intermediate

What is a backed enum in PHP?

A backed enum associates each case with a scalar value like a string or int. This lets you store or compare enum cases easily. Example:<br>

enum Status: string { case Pending = 'pending'; case Approved = 'approved'; }

intermediate

How do you get the scalar value of a backed enum case?

You access the value property of the enum case. For example:<br>

$status = Status::Pending; echo $status->value; // outputs 'pending'

advanced

Can enums in PHP have methods?

Yes! Enums can have methods just like classes. This lets you add behavior related to the enum cases. For example:<br><pre>enum Status { case Pending; case Approved; function label() { return match($this) { self::Pending => 'Waiting', self::Approved => 'Done' }; } }</pre>

Which keyword is used to define an enum in PHP?

A enum

B class

C interface

D const

The enum keyword is used to define enums in PHP.

What type of values can backed enums have in PHP?

A Only strings

B Only integers

C Any data type

D Strings or integers

Backed enums in PHP can have either string or integer scalar values.

How do you access the scalar value of a backed enum case?

A Using the <code>name</code> property

B Using the <code>value</code> property

C Using the <code>getValue()</code> method

D Using the <code>toString()</code> method

The scalar value of a backed enum case is accessed via the value property.

Can PHP enums have methods?

A Only static methods are allowed

B No, enums cannot have methods

C Yes, enums can have methods

D Only abstract methods are allowed

PHP enums can have methods to add behavior related to the enum cases.

Which PHP version introduced enums?

A PHP 8.1

B PHP 7.4

C PHP 8.0

D PHP 8.2

Enums were introduced in PHP 8.1.

Explain what enums are in PHP and why they are useful.

Think about how enums help organize fixed sets of values.

Describe the difference between pure enums and backed enums in PHP.

Consider how backed enums store extra information.