circletest.java

可以让初学者有一个感性的认识

import java.io.*;

public class CircleTest
{
	int radius;

	public CircleTest(){radius=6500;}

	public int getRadius(){return radius;}

	public void setRadius(int newRadius){radius=newRadius;}

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

	public double circlLength(){return 2.0*Math.PI*radius;}
}