C++ help!

[esash]

Hi All,
I am new to linux environment and I am suing ubuntu 9.04. I wrote a simple hello world c++ program:

#include<iostream>

int main(void)
{
cout<<" Hello World! \n";
return 0;
}


and executed: gcc -o sample sample.cpp and got the following error:

sample.cpp: In function ‘int main()’:
sample.cpp:5: error: ‘cout’ was not declared in this scope

Please help. I am new to linux and I know C++ very well. I don't know if I have to install any packages to gcc to execute C++ programs. Also, Please guide me as to how to execute java programs in linux and to use netbeans or eclipse in linux to implement java programs.

Thanks a lot in advance.

Ashraya.

[rcgreen]

#include<iostream>

int main(void)
{
cout<<" Hello World! \n";
return 0;
}

I am not a programmer, but this works

#include<iostream>

using namespace std;

int main(void)
{
cout<<" Hello World! \n";
return 0;
}

[Rubberman]

As rcgreen indicated, you are missing telling the compiler that you want to use namespace std. You could alternatively do this:

#include <iostream>
int main(void)
{
    std::cout << "Hello World!" << std::endl;
    return 0;
}

Note my use of the io manipulator endl. That is preferable in C++ to the use of an embedded newline. It will also make sure that the output is flushed as well as generating the newline.

[tuan_b918]

C++ requires you to have "using namespace std;" in your code, C & Java do not. Hopefully that help.