PURE Java™ 2

Primitives

There are eight kinds of primitives. There are two numeric groups, floating point and integer, plus boolean. These could have been created as classes (as in Smalltalk), but not doing so was an optimization made for better performance. Because primitives are used so often, making them objects would greatly degrade performance. The primitive data types are shown in Table 4.1.

Table 4.1. Java's Primitive Data Types

Primitive	Description
byte	One byte long, signed value.
short	Two-byte long, signed value.
int	Four-byte long, signed value. This is Java's main primitive for doing integral arithmetic.
long	Eight-byte long, signed value.
float	Four-byte long, signed floating point value.
double	Eight-byte long, signed floating point value. ...