NAMES

Fully Qualified Names

6.7

The method

delta

 could try to cast ( 5.4,  15.15) its parameter to be a

Point3d

, but this cast would fail, causing an exception, if the class of

p

 at run

time were not

Point3d

.

A compile time error also occurs in the method warp: it cannot access the pro 

tected member

z

 of its parameter

a

, because while the class

Point

 (the class in

which the reference to field

z

 occurs) is involved in the implementation of a

Point

 (the type of the parameter a), it is not a subclass of

Point

 (the class in

which

z

 is declared).

6.6.8   Example:

private

 Fields, Methods, and Constructors

A private

 class member or constructor is accessible only within the class body in

which the member is declared and is not inherited by subclasses. In the example:

class Point {

Point() { setMasterID(); }

int x, y;

private int ID;

private static int masterID = 0;

private void setMasterID() { ID = masterID++; }

}

the

private

 members

ID,

  m

asterID

, and

setMasterID

 may be used only

within the body of class

Point

. They may not be accessed by qualified names,

field access expressions, or method invocation expressions outside the body of the

declaration of

Point

.

See  8.6.8 for an example that uses a

private

 constructor.

6.7   Fully Qualified Names

Every package, class, interface, array type, and primitive type has a fully qualified

name. It follows that every type except the null type has a fully qualified name.

The fully qualified name of a primitive type is the keyword for that primitive

type, namely

boolean

,

char

,

byte

,

short

,

int

,

long

,

float

, or

double

.

The fully qualified name of a named package that is not a subpackage of a

named package is its simple name.

The fully qualified name of a named package that is a subpackage of another

named package consists of the fully qualified name of the containing package,

followed by  

.

 , followed by the simple (member) name of the subpackage.

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