Several ways to do so, here are some possible one-line approaches:
Use getch()
(need #include <conio.h>
).
Use getchar()
(expected for Enter, need #include <iostream>
).
Use cin.get()
(expected for Enter, need #include <iostream>
).
Use system("pause")
(need #include <iostream>
).
PS: This method will also print Press any key to continue . . .
on the screen. (seems perfect choice for you :))
Edit: As discussed here, There is no completely portable solution for this. Question 19.1 of the comp.lang.c FAQ covers this in some depth, with solutions for Windows, Unix-like systems, and even MS-DOS and VMS.