Alternative function in iostream.h for getch() of conio.h?

just use cin.get();

The conio.h functions are compiler extensions to the language, not part of C or C++. There isn't a direct replacement in standard C++.

For getch(), int ch = std::cin.get(); is probably the closest equivalent -- but bear in mind that this will read from buffered standard input, whereas I think the conio.h getch does an unbuffered read.

Any implementation of clrscr() is going to be very platform-dependent -- not all screens or terminals have a notion of clearing, and those that do have wildly differing ways to access that functionality.

If you need to treat the terminal as something other than a set of character streams, your best bet is probably to look for a library which hides the details of the underlying terminal, screen or console from you. If you're on a UNIXish system, look at the curses or ncurses library; I don't know of any suggestions for other OSes.

getch() and clrscr() will work with C++. Include conio.h

However, if you CANNOT (for some reason) include conio.h,

how about cin>>dummy_var with a display message asking the user to press enter?