Classes - The Java Language Specification - page 241

void move(float dx, float dy) { x += dx; y += dy; }
public String toString() { return "("+x+","+y+")"; }
}
Here, the class Point has two members that are methods with the same name, move . The
overloaded move method of class Point chosen for any particular method invocation is
determined at compile time by the overloading resolution procedure given in § 15.12 .
In total, the members of the class Point are the float instance variables x and y declared
in Point , the two declared move methods, the declared toString method, and the members
that Point inherits from its implicit direct superclass Object (§ 4.3.2 ) , such as the method
hashCode . Note that Point does not inherit the toString method of class Object because that
method is overridden by the declaration of the toString method in class Point .
Example 8.4.9-2. Overloading, Overriding, and Hiding
Click here to view code image
class Point {
int x = 0, y = 0;
void move(int dx, int dy) { x += dx; y += dy; }
int color;
}
class RealPoint extends Point {
float x = 0.0f, y = 0.0f;
void move(int dx, int dy) { move((float)dx, (float)dy); }
void move(float dx, float dy) { x += dx; y += dy; }
}
Here, the class RealPoint hides the declarations of the int instance variables x and y of
class Point with its own float instance variables x and y , and overrides the method move
of class Point with its own move method. It also overloads the name move with another
method with a different signature (§ 8.4.2 ).
In this example, the members of the class RealPoint include the instance variable color
inherited from the class Point , the float instance variables x and y declared in RealPoint ,
and the two move methods declared in RealPoint .
Which of these overloaded move methods of class RealPoint will be chosen for any par-
ticular method invocation will be determined at compile time by the overloading res-
olution procedure described in § 15.12 .
This following program is an extended variation of the preceding program: