shapecircle.java

来自「实例精华」· Java 代码 · 共 39 行

/**
*<DL><DT><b>功能：</b><DD>抽象类Shapes的子类II</DD></DL>
*@author Alex Wen
*@version V1.0 2003/12
*/
public class ShapeCircle extends Shapes
{
	private double r;
	public ShapeCircle()
	{
		setRadius(0.0);
	}
	public ShapeCircle(double ra)
	{
		setRadius(ra);
	}
	public void setRadius(double rad)
	{
		this.r=rad;
	}
	/**
	*实现父类的抽象方法
	*/	
	public double perimeter()
	{
		return 2.0*Math.PI*r;
	}
	public String getType()
	{
		return "圆";
	}
	public static void main(String args[])
	{
		ShapeCircle sc=new ShapeCircle(5);
		System.out.println("形状："+sc.getType());
		System.out.println("周长："+sc.perimeter());
	}
}