circle.java

Java 程序设计源码 只提供了部分

class Circle {
	final static double PI = 3.14;
	private double dbRadius = 1;
	
	public Circle(double dbRadius) {
		this.dbRadius = dbRadius;
	}

	public double Area() {
		double area;

		area = 2 * PI * dbRadius * dbRadius;

		return area;
	}
}
	
public class CircleDemo {
	public static void main(String[] args) {
		Circle cir = new Circle(3.5);
	
		System.out.println(cir.Area());
	} 
}