Issues with iostream and std namespace?

[jfigaro]

Hey, guys! Just recently started C++ and am having an issue with compiling a simple script.

Here is the source:

#include <iostream.h>

using namespace std;

int main() {
cout << "Hello, world!";
cout << "I'm a C++ program";
return 0;
}

I'm using Mono to compile it (via gmcs) and it gives me the following errors:

hello-world.cpp(2,0): error CS1024: Wrong preprocessor directive
hello-world.cpp(3,7): error CS1041: Identifier expected: `namespace' is a keyword
hello-world.cpp(3,20): error CS1003: Syntax error, `.' expected
hello-world.cpp(5,12): error CS8032: Internal compiler error during parsing, Run with -v for details

Any ideas on why this is giving me trouble?

[Albatross]

Some (all) of the errors are funky, and that last one hints that you maybe should run the compiler with -v as an argument, if you know how.

This looks like a reinstall-fixable problem, though.

-Albatross

[Disch]

well it should be <iostream>, not <iostream.h>

But your errors don't really make sense.

I didn't know Mono was a compiler? I thought it was a .net runtime environment? Are you sure you're actually using a C++ compiler?

[Bazzy]

Mono is for .Net, if you are using C++ ( ie not C# or C++/CLI ) you should use a C++ compiler

[Albatross]

Actually, Disch++. Try compiling it with g++ and see if you get similar or the same errors. I also didn't know Mono is an actual compiler.

-Albatross

[jfigaro]

Wow, guys. That is embarrassing... thank you for all of your help. I've got gcc and have attempted to use it - it still seems like it's having an issue finding iostream. This is the output from gcc:

hello-world.c:1:20: error: iostream: No such file or directory
hello-world.c:3: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘namespace’
hello-world.c: In function ‘main’:
hello-world.c:6: error: ‘cout’ undeclared (first use in this function)
hello-world.c:6: error: (Each undeclared identifier is reported only once
hello-world.c:6: error: for each function it appears in.)

[Bazzy]

Use g++ instead of gcc or call gcc -std=c++98 -lstdc++
And remember about <iostream.h>

[Galik]

//#include <iostream.h> // NOT this!
#include <iostream> // Use this

using namespace std;

int main() {
cout << "Hello, world!";
cout << "I'm a C++ program";
return 0;	
}

Compile with:

g++ -o prog prog.cpp

[jfigaro]

Thanks a ton, everyone. That last suggestion you made fixed all of my problems, Bazzy.

[jfigaro]

Nice, Galik. Thank you! I can actually move on in the learning process now, thanks to all of you.