OnJava8-Examples/polymorphism/PolyConstructors.java
2015-11-03 12:00:44 -08:00

37 lines
807 B
Java

// polymorphism/PolyConstructors.java
// Constructors and polymorphism
// don't produce what you might expect.
class Glyph {
void draw() { System.out.println("Glyph.draw()"); }
Glyph() {
System.out.println("Glyph() before draw()");
draw();
System.out.println("Glyph() after draw()");
}
}
class RoundGlyph extends Glyph {
private int radius = 1;
RoundGlyph(int r) {
radius = r;
System.out.println("RoundGlyph.RoundGlyph(), radius = " + radius);
}
@Override
void draw() {
System.out.println("RoundGlyph.draw(), radius = " + radius);
}
}
public class PolyConstructors {
public static void main(String[] args) {
new RoundGlyph(5);
}
}
/* Output:
Glyph() before draw()
RoundGlyph.draw(), radius = 0
Glyph() after draw()
RoundGlyph.RoundGlyph(), radius = 5
*/