Reference on primitive types - Multimedia Introduction to Programming Using Java - page 212

Chapter 6

Reference on Primitive Types

OBJECTIVES

• Provide a reference on Java's primitive types.

INTRODUCTION
A type describes a set of values together with operations on them. For example,
mathematical type integer describes the set of all integers together with opera-
tions like addition + and multiplication * . Each variable in a Java program has a
type, which defines the values that can be associated with the variable. Each
expression has a type, which depends on the type of its operands.
Java has two kinds of types: primitive types and class types . Primitive types
are built into Java. A class type, or simply class, is defined in a program, by a
class definition . In this chapter, we describe the primitive types.
Below, we list the primitive types of Java, along with the set of values in
them and the amount of memory used to hold their values.

Type Range of values Memory used

1 byte (8 bits) byte -128..127

-2 15 ..2 15 -1 2 bytes (16 bits) short

-2 31 ..2 31 -1 4 bytes (32 bits) int

-2 63 ..2 63 -1

8 bytes (64 bits)

long

-3.4028235E38 to -1.4E-45 4 bytes (32 bits) float

1.4E-45 to 3.4028235E38

-1.7676931348623157E308 to 0 8 bytes (64 bits)

double

0 to 1.7676931348623157E308

Unicode characters 2 bytes (16 bits)

char

false , true 1 byte

boolean