Question

java

Consider the following class definition:

     public class Circle {
        private double radius;
        public Circle (double r) {

radius = r ; }

         public double getArea(){
             return Math.PI * radius * radius;

         }
         public double getRadius(){

             return radius;
         }

}

1. a) Write a toString method for this class. The method should return a string containing the radius and area of the circle; For example “The area of a circle with radius 2.0 is 12.1.”

2. b) Writeaequalsmethodforthisclass.ThemethodshouldacceptaCircleobjectasan argument. It should return true if the argument object contains the same data as the calling object, or false otherwise.

3. c) WriteagreaterThanmethodforthisclass.ThemethodshouldacceptaCircleobject as an argument. It should return true if the argument object has an area that is greater than the area of the calling object, or false otherwise.

Answer 1

public class Circle {
    private double radius;

    public Circle(double r) {
        radius = r;
    }

    public double getArea() {
        return Math.PI * radius * radius;
    }

    public double getRadius() {
        return radius;
    }

    // a)
    @Override
    public String toString() {
        return "The area of a circle with radius " + radius + " is " + getArea() + ".";
    }

    // b)
    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Circle circle = (Circle) o;
        return Double.compare(circle.radius, radius) == 0;
    }

    // c)
    public boolean greaterThan(Circle circle) {
        return getArea() > circle.getArea();
    }
}