linking <iostream.h> in linux using gcc

please use g++ not gcc to compile it

• cout is defined in the std:: namespace, you need to use std::cout instead of just cout.
• You should also use #include <iostream> not the old iostream.h
• use g++ to compile C++ programs, it'll link in the standard c++ library. gcc will not. gcc will also compile your code as C code if you give it a .c suffix. Give your files a .cpp suffix.