1.2.372. Don’t Pollute Global Space

Avoid creating definitions in the global name space.

The global namespace is the default namespace, where all functions, classes, constants, traits and interfaces live. The global namespace is also known as the root namespace.

In particular, PHP native classes usually live in that namespace. By creating functions in that namespace, the code may encounter naming conflict, when the PHP group decides to use a name that the code also uses. This already happened in PHP version 5.1.1, where a Date native class was introduced, and had to be disabled in the following minor version.

Nowadays, conflicts appear between components, which claim the same name.

<?php

// This is not polluting the global namespace
namespace My/Namespace {
     class X {}
}

// This is polluting the global namespace
// It might be in conflict with PHP classes in the future
namespace {
     class X {}
}

?>

See also Using namespaces: fallback to global function/constant.

1.2.372.1. Connex PHP features

1.2.372.1.1. Suggestions

  • Create a namespace for your code, and store your definition there.

1.2.372.1.2. Specs

Short name

Php/DontPolluteGlobalSpace

Rulesets

All, Analyze

Exakat since

2.1.7

PHP Version

All

Severity

Minor

Time To Fix

Quick (30 mins)

Precision

High

Available in

Entreprise Edition, Exakat Cloud