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c++namespacesiostreamcout

Error: 'cout' : undeclared identifier; though I've included iostream header file in program

I am trying to compile the simple program below. But, it's not compiling & gives error:

error C2065: 'cout' : undeclared identifier

I want to ask you that why this program doesn't work though I've included iostream header file in it?

#include <iostream>

void function(int) { cout << “function(int) called” << endl; }
void function(unsigned int) { cout << “function(unsigned int) called” << endl; }
    int main()
    {
        function(-2);
        function(4);
        return 0;
    }

Thanks in advance.

Solution

  • The cout stream is defined in the std namespace. So to name it you write:

    std::cout

    If you want to shorten this to cout then you can write 

    using namespace std;

    or 

    using std::cout;

    before writing cout.

    Any good documentation source will tell you which namespace contains an object. For instance: http://en.cppreference.com/w/cpp/io/cout