see machine instruction. An int (short for integer) is a type of integer variable that is essentially equivalent to either a short or a long, depending on the compiler you are using. A 16-bit compiler such as Borland C++ 3.1 has 16-bit int s, which are the same size as short s. A 32-bit compiler such as DJGPP (the compiler on the CD-ROM that comes with this book) has 32-bit int s, which are the same size as long s. Of course, pedants will point out that it is not absolutely guaranteed that an int is the same size as either a short or a long; it's theoretically possible that all three of these variable types are different in size. However, at this writing, all commonly available C++ compilers for microcomputers in fact equate an int with either a short or a long. and it does not appear likely that this situation will change in the near future. An integer variable is a C++ representation of a whole number. Unlike mathematical integers, C++ integers have a limited range, depending on their types; see the individual types char, short, int, and long for details. The type bool is sometimes also considered an integer variable type.