Namespaces

A namespace is a container for identifiers—such as variable, function, or type names—that provides a context for disambiguation. By grouping related symbols and allowing them to be referred to with qualified names, namespaces help prevent naming conflicts and improve code organization.

Namespaces define scope boundaries and resolution rules. Access is typically achieved by prefixing a name with the namespace, or by introducing an alias or import so that the name can be used unqualified within a limited region.

Examples: In C++, code can declare a namespace and refer to its members as Foo::bar, or bring names into scope with using. In Python, modules act as namespaces and attributes accessed as module.attr; packages provide nested namespaces. In Java, packages serve as namespaces and fully qualified names (for example, com.example.MyClass) avoid collisions. In XML, namespaces distinguished by xmlns declarations ensure elements from different vocabularies do not collide.

Design considerations include balancing explicit qualification against readability, and choosing appropriate scoping strategies. Aliasing can simplify code but may reintroduce ambiguity. Some languages offer anonymous or internal namespaces (for example, anonymous namespaces in C++) to limit visibility.