Inheritance and
is-a relationship
“Is-a'' also implies, that we can use a circle everywhere |
where a point is expected. For example, write a function or
method, say move(), which should move a point in x |
direction can be written as follows. |
move(Point apoint, int deltax) { |
apoint.setX(apoint.getX() + deltax)
} |
As a circle inherits from a point, you can use this function |
with a circle argument to move its center point and, hence,
the whole circle: |