please I try using iostream.h but it is not compiling

Answer 1

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

Answer 2

because iostream it's for old C++... and Zen...use the main arguments for better performance. ..like this

int main (int argc, char* argc [])

its just a tip...

hope that this helps ;-)...good luck!

Answer 3

if you are using the new ide like codeblocks then you will have to use iostream only and later write using namespace std;