<xxxx.h> was the old way for standard header files. The new header files drop the 'h'. Like so:
Code:
#include <iostream>
using namespace std;
int main()
{
cout << "Hello world!" << endl;
return 0;
}
The old ".h" way has been deprecated, so although it is still possible to use that now, that won't always be the case in the future. What you should do is use the new libraries.
Now as for that whole std thingie, that's a namespace. In the new and improved libraries, all of the identifiers have been placed in a namespace called std to avoid potential name conflicts. The easiest way to ensure that you are using the whole std namespace is as shown above. There are other ways, however, that some people will argue are better/worse.
Code:
#include <iostream>
using std::cout;
using std::endl;
int main()
{
cout << "Hello World!" << endl;
return 0;
}
/* OR */
#include <iostream>
int main()
{
std::cout << "Hello World!" << std::endl;
return 0;
}
If you feel the need to know exactly what namespaces are, a quick search will probably yield many answers.