Circle

/* Eva Goins
 * Chapter 6
 * Description: The class Circle has the fields radius (double)
 *      and PI (final double), the constructors Circle that allows
 *      immediate input of the radius, and the no args constructor.
 *      The class also uses methods setRadius to set the radius
 *      should it be user-input, getRadius to obtain the radius
 *      currently set, getArea to calculate the area, getDiameter
 *      to calculate the diameter, and getCircumference to calculate
 *      the circumference. All non-constructor methods return a
 *      double value.
 */

 public class Circle
 {
    double radius;
    final double PI = 3.14159;

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

    public Circle()
    {
        radius = 0.0;
    }

    public void setRadius(double rad)
    {
        radius = rad;
    }

    public double getRadius()
    {
        return radius;
    }

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

    public double getDiameter()
    {
        return radius * 2;
    }

    public double getCircumference()
    {
        return 2 * PI * radius;
    }
 }