C++ Primer Plus

The short, int, long, and long long Integer Types

Computer memory consists of units called bits. (See the “Bits and Bytes” sidebar later in this chapter.) By using different numbers of bits to store values, the C++ types short, int, long, and long long can represent up to four different integer widths. It would be convenient if each type were always some particular width for all systems—for example, if short were always 16 bits, int were always 32 bits, and so on. But life is not that simple. No one choice is suitable for all computer designs. C++ offers a flexible standard with some guaranteed minimum sizes, which it takes from C. Here’s what you get:

• A short integer is at least 16 bits wide.

• An int integer is at least as big as short.