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C++ Namespaces:
What are C++ Namespaces?
- In C++, namespaces allow us to group named entities that have global scope into narrower scope giving them namespace scope.
- It is like a container for identifiers and it put the name of its members in a distinct space so that they don’t conflict with the names in other namespaces or global namespace.
- Namespaces are used to organize too many classes so that it is easy to handle the application. The class of a namespace can be accessed by using namespacename::classname.
Let us understand namespace through an example:
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#include <iostream> using namespace std; namespace A { void sayWelcome() { cout<<"Welcome to first namespace"<<endl; } } namespace B { void sayWelcome() { cout<<"Welcome to second namespace"<<endl; } } int main() { A::sayWelcome(); B::sayWelcome(); return 0; } |
Rules for declaring Namespace
- Its declarations appear only at global scope.
- Its declarations can be nested within another namespace.
- Its declarations don’t have access specifiers (public or private).
- In this we do need to give a semicolon after the closing brace of definition.