what is the function of using namespace std and how it exacutes a function when used before cin or cout as std::cin.
Using namespace
@Tej_narayan A namespace is a declarative region that provides a scope to the identifiers (the names of types, functions, variables, etc) inside it. Namespaces are used to organize code into logical groups and to prevent name collisions that can occur especially when your code base includes multiple libraries.
Also refer this: https://www.tutorialspoint.com/What-does-using-namespace-std-mean-in-Cplusplus
Hope this helps 
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