Creating Superclasses and Subclasses

AP Computer Science A· difficulty 3/5

public abstract class Shape {
    public abstract double area();
    public String describe() { return "Area=" + area(); }
}
public class Circle extends Shape {
    public double area() { return 3.14; }
}
Shape s = new Circle();
System.out.println(s.describe());

What is printed?

A
$Area=0.0$
B
$Area=3.14$
check_circle
C
$Area=$
D
$Compile-time error$

Explanation

describe() calls area(); dynamic dispatch invokes Circle.area(), returning 3.14.

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