Additional Java Syntax - Building Java Programs: A Back to Basics Approach - page 1125

Appendix D
Additional Java Syntax

This appendix briefly covers several features of Java that are not otherwise shown in
the textbook. It is not intended to be a complete reference; see Sun's Java Language
Specification and Java Tutorial online for more detailed coverage of these language
features.

Primitive Types: byte , short , long , float

In this textbook we have focused our attention on four primitive data types: int ,
double , char , and boolean . Java has four additional primitive types that are used in
certain special situations. Three of these additional types ( byte , short , and long )
are variants of int that use a different amount of memory, providing a tradeoff
between memory consumption and the range of numbers that can be represented. The
fourth, float , is a variant of double that uses half the memory. It can be useful in
certain applications where reduced memory usage and faster computation is more
important than extremely high numeric accuracy, such as in computer games.

Type Description Range Usage

8-bit (1-byte) integer - 128 to 127 Reading data from an input source one

byte at a time

byte

short 16-bit (2-byte) integer

- 32,768 to 32,767 Saving memory when creating many

integers

64-bit (8-byte) integer Representing very large integers that

may not fit into the range of int

- 2 63 to (2 63 - 1)

long

float 32-bit (4-byte) real
number

roughly 3.4E - + 38 Saving memory when creating many

real numbers

to 3.4E + 38

Many of the operators and much of the syntax that you have used with int and
double work with these types. Two of these types use a suffix letter at the end of
their literal values: F for float, and L for long . The following code declares a variable
of each type:

byte var1 = 63;
short var2 = -16000;
long var3 = 1234567890123456L;
float var4 = 1.2345F;

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