#include <iostream.h> // This is a very simple C++ program int main() { cout << "Success\n"; return 0; }It is very straight forward, but it shows several important differences to ANSI C.
Firstly, the #include directive now brings in the C++ iostream.h library instead of C's stdio.h. In practice most compilers will accept ANSI C header files and stdio.h features can still be used, but we shall not be doing so here.
Second, the C++ comment delimiter is used. This is a double slash (oblique), //, at the beginning of the comment. It marks the remainder of the line as to be ignored. It does not continue across lines. C++ compilers will also recognise the C style of bracketted comment.
Functions like main are declared in the same way as in C. main is always expected to be of type int in C++, however.
The output statement now uses the standard output stream, cout, and the output operator <<. This is a much simpler way to achieve I/O than in ANSI C.
In general C++ is a superset of ANSI C, but programmers tend to use its new versions of certain features in preference to ANSI C features. There are a couple of small incompatibilities, as we shall see elsewhere in these notes.