Hello World

     #include <iostream>
     using namespace std;
     
     int main (int argc, char** argv) {
         cout << "Hello world" << endl;
         return 0;
     }

• Valid C programs are also valid C++ programs! You may be accused of not using C++ properly but the program will work.

• main is still the primary function that is looked for. When main finishes the program finishes.

• The include file doesn't use a .h extension. This is a very new thing and many, many programs still use the old extension. It's not currently an error to use it but you may get a warning when using new C++ compilers.

• The line

  using namespace std;

  is unusual. Just put this in your C++ programs after the includes and you'll be fine.

• Output is usually done completely differently than in C.