using Directive

using Directive

• A C++ program can be divided into different namespaces. A namespace is a part of the program in which certain names are recognized; outside of the namespace they’re unknown.
• The directive using namespace std; says that all the program statements that follow are within the std namespace.
• Various program components such as coutare declared within this namespace. If we didn’t use the using directive, we would need to add the stdname to many program elements. e.g.

        std::cout<< "Welcome to this course\n";

• To avoid adding std:: dozens of times in programs we use the usingdirective instead.