构造函数的应用

package nine;

public class nine_1 {

	public static void main(String[] args) {
		nine_1 circle_1=new nine_1();//声明nine的对象nine_1,调用无参数的构造函数;
		nine_1 circle_2=new nine_1(10,10);//声明nine的对象nine_2,调用有两个参数的构造函数
		System.out.println("长是: " + circle_1.width +  " " +"宽是:" +circle_1.height + "面积是: " + circle_1.getArea()  + "周长是: " + circle_1.getPerimeter());
		System.out.println("长和宽是: " + circle_2.width + " " +"宽是:" +circle_2.height  + "面积是:" + circle_2.getArea() + "周长是:" + circle_2.getPerimeter());
	}
	public double width,height;
	nine_1()//默认调用的构造函数,给width和height赋初值为1;
	{
		width=1;
		height=1;
	}
	nine_1(double a,double b)//有两个参数的构造函数，给width和height赋传入的值;
	{
		width=a;
		height=b;
	}
	public double getArea() {//计算面积的方法
		return width*height;
	}
	public double getPerimeter()//计算周长的方法
	{
		return 2*(width+height);
	}

}