What is Namespace in C++?


Namespace is a new concept introduced by the ANSI C++ standards committee. For using identifiers it can be defined in the namespace scope as below.


using namespace std;

In the above syntax "std" is the namespace where ANSI C++ standard class libraries are defined. Even own namespaces can be defined.


namespace namespace_name
//Declaration of
// variables, functions, classes, etc.

Example :

#include <iostream.h> using namespace std; namespace Own
int a=100;
} int main()
cout << "Value of a is:: " << Own::a;
return 0;

Result :

Value of a is:: 100

In the above example, a name space "Own" is used to assign a value to a variable. To get the value in the "main()" function the "::" operator is used.

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