How can I resolve the "cout was not declared in this scope" error?

Question

just a simple program but can anyone point out why this error is occuring, (i am using dev C++ version 5.11)

#include <stdio.h>
#include <conio.h>

class animal
{
 public :
    void sound();

     void eat() ;

};
void animal::eat()
{
        cout<<"i eat animal food" ; 


}


void animal::sound()
{
        cout<<"i sound like an animal" ;

     }

void main()
{
    animal a ;
    a.sound()
    a.eat()
    getch()
}

the error is coming like this:

In member function 'void animal::eat()':
15  4   C:\Users\chetna\Documents\Untitled1.cpp [Error] 'cout' was not declared in this scope
1   0   C:\Users\chetna\Documents\Untitled1.cpp In file included from C:\Users\chetna\Documents\Untitled1.cpp

Answer 1

At least you have to include

#include <iostream>

and

using namespace std;

The name cout is declared in the namespace std . So either use the using directive as shown above or use a qualified name (that is better) like

std::cout<<"i eat animal food" ; 

An alternative approach is to use a using declaration. For example

#include <iostream>

using std::cout;

//...
void animal::eat()
{
        cout<<"i eat animal food" ; 
}

And remove this directive

#include <stdio.h>

Also place semicolons

a.sound();
a.eat();
getch();

Pay attention to that the function main shall be declared like

int main()

Answer 2

Please, stop using the old Borland C++ et al.

Use a modern standards compliant C++ compiler (g++, clang, Microsoft Visual Studio) instead.

Do not use conio.h, it is a very old compiler specific library, not a standard one.

Do not use stdio.h it is not a bad library, but it declares several C functions, not C++ ones.

Declare your main function as

int main()

not void main() , because standard C++ needs the main function to return an int (0 for success).

Instead of using cout , use std::cout , because it is an object representing the standard output defined inside the std namespace.

Answer 3

This helped me. I faced this error while I was setting up C++ with MinGW for vscode for cp(competitive programming).

IOSTREAM FILE

Error Message

It was nowhere to be found. Refer the above screenshots, If you have that extended error message, Then possibly there is an issue with your iostream library file. If you using Vscode, CTRL + Click .

• Read carefully the error is just the space between the ostreamcout line 61.
• Save and now try to run. Happy Coding.