Java Reference
In-Depth Information
Note, however, that it is not an error for the name of a class to also name a type that
otherwise might be imported by a type-import-on-demand declaration (§
7.5.2
) in the
package test;
import java.util.*;
class Vector {} // not a compile-time error
the declaration of the class
Vector
is permitted even though there is also a class
java.util.Vector
. Within this compilation unit, the simple name
Vector
refers to the class
test.Vector
, not to
java.util.Vector
(which can still be referred to by code within the com-
pilation unit, but only by its fully qualified name).
Example 7.6-2. Scope of Top Level Types
package points;
class Point {
int x, y; // coordinates
PointColor color; // color of this point
Point next; // next point with this color
static int nPoints;
}
class PointColor {
Point first; // first point with this color
PointColor(int color) { this.color = color; }
private int color; // color components
}
This program defines two classes that use each other in the declarations of their class
members. Because the class types
Point
and
PointColor
have all the type declarations in
package
points
, including all those in the current compilation unit, as their scope, this
program compiles correctly. That is, forward reference is not a problem.
Example 7.6-3. Fully Qualified Names
class Point { int x, y; }
