C++ Compiling Error

Mohan Giri · 05-09-2005, 10:56 AM

Hello everyone,
I have compiled my first c++ program in Windows environment. (MS VC++). But I am getting error for the simple program.

My program is:

#include<stdio.h>
main()
{
cout<<"Welcome to C++";
cout<<"All the best";
}

Error is

--------------------Configuration: first - Win32 Debug--------------------
Compiling...
hello1.cpp
e:\giri\c++\ex\first\hello1.cpp(4) : error C2065: 'cout' : undeclared identifier
e:\giri\c++\ex\first\hello1.cpp(4) : error C2297: '<<' : illegal, right operand has type 'char [10]'
e:\giri\c++\ex\first\hello1.cpp(5) : warning C4508: 'main' : function should return a value; 'void' return type assumed
Error executing cl.exe.

hello1.obj - 2 error(s), 1 warning(s)

Can anybody tell me what is the problem.

Iron_Cross · 05-09-2005, 11:18 AM

You need to include

Code:

#include <iostream>
using namespace std;

int main(void)
{
cout<<"Welcome to C++";
cout<<"All the best";
cout<< endl;

return 0;
}

There's several fixes I did there...

1.) I included iostream not stdio. << is part of the iostream header. It's also a part of the std namespace, so I included a using statment. Otherwise, every time I referenced cout I'd have to use std::cout it's much shorter to write the using statement.
2.) the main method now returns a value (int) and it tells the compiler that there are no arguments (void). It's mainly just good programming practice, it's not necesarry though.
3.) I included a call to endl which flushes the output buffer. Again, it's just good practice to flush the output buffer when you're done writing. That way you make sure all changes get made.
4.) I returned a value (of type int). I returned 0 which lets the operating system know that there was no errors during execution.

Hope that helps.

EDIT: also, if your book is teaching you put the .h at the end of your include statments, then chances are that your book is a bit outdated. It's not standard to do that anymore, you should leave it off.

Mohan Giri · 05-09-2005, 11:25 AM

I fixed the error. I have worked in C environment this long. So mistakenly I include <stdio.h> hearder file instead of <iostream.h>. Thanks for your try.

Iron_Cross · 05-09-2005, 04:43 PM

Please re-read my post.

Mohan Giri · 05-10-2005, 04:24 PM

Tell me why we are including "using namespace std" statement in our code. And if we use the code while specifying ".h" in iostream include statement getting error like

--------------------Configuration: fibonaci - Win32 Debug--------------------
Compiling...
fibonaci.cpp
e:\giri\c++\ex\fibonaci\fibonaci.cpp(2) : error C2871: 'std' : does not exist or is not a namespace
Error executing cl.exe.

fibonaci.obj - 1 error(s), 0 warning(s)

what is the reason?? Can you explain me??