例题4-3 使用Lader类创建两个对象laderOne laderTwo

class Lader{
 double above,bottom,height;
 Lader(){}
 Lader(double a,double b,double h){
  above=a;
  bottom=b;
  height=h;
  }
  public void setAbove(double a){
   above=a;
   }
   public void setBottom(double b){
    bottom=b;
    }
    public void setHeight(double h){
     height=h;
     }
     double Area(){
      return (above+bottom)*height/2.0;
      }
 }
 public class Example4_3{
  public static void main(String[] args){
   double area1=0,area2=0;
   Lader laderOne,laderTwo;
   laderOne =new Lader();
   laderTwo =new Lader(1,2,3);
   laderOne.setAbove(11);
   laderOne.setBottom(22);
   laderOne.setHeight(33);
   area1=laderOne.Area();
   area2=laderTwo.Area();
   System.out.println("laderOne的above,bottom和height："+laderOne.above+","+laderOne.bottom+","+laderOne.height);
   System.out.println("laderOne的面积："+area1);
   System.out.println("laderTwo的above,bottom和height："+laderTwo.above+","+laderTwo.bottom+","+laderTwo.height);
   System.out.println("laderTwo的面积："+area2);
   }
  }

 

经过一系列的查找，终于把错误全找没了。。。。。。。。。。。。。。。。。