Namespace declaration syntax in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of a namespace in PHP?

A namespace in PHP helps organize code by grouping related classes, functions, and constants to avoid name conflicts.

beginner

How do you declare a namespace in PHP?

Use the namespace keyword followed by the namespace name and a semicolon. Example: namespace MyApp\Utils;

intermediate

Can you declare multiple namespaces in one PHP file?

Yes, but only if you use the bracketed syntax for each namespace block. Example:<br>namespace A { /* code */ } namespace B { /* code */ }

intermediate

What happens if you declare a namespace after some code in a PHP file?

The namespace declaration must be the first statement in the file (except for declare statements or comments). Declaring it after code causes a syntax error.

intermediate

Explain the difference between bracketed and unbracketed namespace syntax in PHP.

Unbracketed syntax declares a namespace for the whole file with a semicolon:<br>namespace MyApp;<br>Bracketed syntax wraps code in braces to allow multiple namespaces in one file:<br>namespace MyApp { /* code */ }

Which keyword is used to declare a namespace in PHP?

A use

B class

C namespace

D package

The namespace keyword declares a namespace in PHP.

Where must the namespace declaration appear in a PHP file?

A At the end of the file

B Before any other code except declare statements or comments

C Only after all functions are declared

D Anywhere in the file

Namespace declarations must be the first statement in the file, except for declare statements or comments.

How do you declare multiple namespaces in one PHP file?

A Using the use keyword multiple times

B Using multiple unbracketed namespace declarations

C It is not possible

D Using bracketed syntax for each namespace block

Multiple namespaces require bracketed syntax blocks for each namespace.

What symbol ends an unbracketed namespace declaration?

A ;

B {}

C :

D ,

Unbracketed namespace declarations end with a semicolon.

Which of these is a valid namespace declaration in PHP?

A namespace MyApp\Utils;

B namespace = MyApp.Utils;

C namespace: MyApp.Utils;

D namespace MyApp.Utils{}

The correct syntax uses the keyword namespace followed by the name and a semicolon.

Describe how to declare a namespace in PHP and explain the difference between bracketed and unbracketed syntax.

Think about how you organize code into groups and how PHP lets you do that in one or many blocks.

What are the rules about where you can place a namespace declaration in a PHP file?

Consider what PHP expects at the start of a file before any code runs.