package homework2; public class Rect { //成员变量 public double width; public double height; //带参的构造方法 Rect(double width, double height) { this.width=width; this.height=height; } //不带参的构造方法 Rect() { this.width=10; this.height=10; } //成员方法 面积 double area() { return width*height; } //成员方法 周长 double perimeter() { return 2*(width+height); } }
package homework2;
public class PlainRect extends Rect
{
//添加两个成员变量
public double startX;
public double startY;
//添加无参构造方法
PlainRect()
{
startX=0;
startY=0;
width=0;
height=0;
}
PlainRect(double width,double height,double startX,double startY)
{
this.width=width;
this.height=height;
this.startX=startX;
this.startY=startY;
}
//添加成员方法
boolean isInside(double x,double y)
{
if(x>=startX&&x<=(startX+width)&&y<startY&&y>=(startY-height))
{
return true;
}
else
return false;
}
}
package homework2; public class Text_PlainRect { public static void main(String[] args) { PlainRect re=new PlainRect(20,10,10,10); System.out.println("矩形坐标为:("+re.startX+","+re.startY+")"); System.out.println("矩形的长为:"+re.width+"矩形的高为:"+re.height); System.out.println("矩形的面积为:"+re.area()); System.out.println("矩形的周长为:"+re.perimeter()); if(re.isInside(25.5,13)==true) { System.out.println("断点(25.5,13)在矩形内"); } else { System.out.println("断点(25.5,13)不在矩形内"); } } }