Variables - Beginning Java with WebSphere - page 140

Figure 5-4.

This explanation of reference variables was necessary because there is another category of variables called
primitive variables. A primitive variable actually holds the value assigned to it. One of the reasons a primitive variable
holds the assigned value is because each primitive variable type is fixed in size (unlike complex objects such as a
String or Employee, which can vary in size). Java stores numeric information, single characters, and Boolean values
(true or false) in primitive variables. Within the numeric types, the variables store either whole numbers (integers)
or floating points (numbers with decimals). A list of primitive variable types and their characteristics can be seen
in Table 5-1 .

Table 5-1.

Primitive Type Value Type Value Range Space

Allocated

Notes

boolean logical true or false default is false

char single character any of Unicodes's 65,436 characters 16 bits single quotes to

specify value

byte whole number -128 to 127 8 bits

short whole number - 32,768 to 32,767 16 bits

int whole number -2,147,483,648 to 2,147,483,647 32 bits

long whole number - 9*10**18 to 9*10**18-1 64 bits

float floating point Up to 7 digits of precision 32 bits Rounds values > limit

double floating point Up to 15 digits of precision 64 bits Rounds values > limit