A **namespace** in C++ is used to declare a region, which provides scope to identifiers (the names of functions, variables, types, and so on) inside it.

It is common to see the `using namespace std` line in almost every C++ program. However, there are programs that run without it. We can omit the `using namespace std` line in our C++ program by using only the `std` keyword, followed by the scope resolution operator, that is, `::`. 

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## Example
The code given below shows us how to create a program that omits the `using namespace std` line:

#include <iostream>
#include <string>

int main() {
  std::string greeting = "Hello World";
  std::cout << greeting;
  return 0;
}


## Code explanation
From the code given above, we can see that we are able to write a code without using the `using namespace std` line. We can do this by replacing the `using namespace std` line with the `std` keyword, followed by the scope resolution operator, that is, `::`.

How to omit "using namespace std" in C++?

Example

Code explanation