TYPES, VALUES, AND VARIABLES

Variables

4.5

Imported types ( 7.5); here the type

Random

, imported from the type

java.util.Random

 of the package

java.util

, is declared

Fields, which are the class variables and instance variables of classes ( 8.3),

and constants of interfaces ( 9.3); here the field

divisor

 in the class

MiscMath

is declared to be of type

int

Method parameters ( 8.4.1); here the parameter

l

 of the method

ratio

 is

declared to be of type

long

Method results ( 8.4); here the result of the method

ratio

 is declared to be of

type

float

, and the result of the method

gausser

 is declared to be of type

double

Constructor parameters ( 8.6.1); here the parameter of the constructor for

MiscMath

 is declared to be of type

int

Local variables ( 14.3,  14.12); the local variables

r

 and

val

 of the method

gausser

 are declared to be of types

Random

 and

double[]

 (array of

double

)

Exception handler parameters ( 14.18); here the exception handler parameter

e

 of the

catch

 clause is declared to be of type

Exception

and in expressions of the following kinds:

Class instance creations ( 15.8); here a local variable

r

 of method

gausser

 is

initialized by a class instance creation expression that uses the type

Random

Array creations ( 15.9); here the local variable

val

 of method

gausser

 is ini 

tialized by an array creation expression that creates an array of

double

 with

size 2

Casts ( 15.15); here the

return

 statement of the method

ratio

 uses the

float

 type in a cast

The

instanceof

 operator ( 15.19.2); here the

instanceof

 operator tests

whether

e

 is assignment compatible with the type

ArithmeticException

4.5   Variables

A variable is a storage location and has an associated type, sometimes called its

compile time type

, that is either a primitive type ( 4.2) or a reference type ( 4.3).

A variable always contains a value that is assignment compatible ( 5.2) with its

type. A variable's value is changed by an assignment ( 15.25) or by a prefix or

postfix

++

 (increment) or

 (decrement) operator ( 15.13.2,  15.13.3,  15.14.1,

 15.14.2).

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