java类学习

package 计算长方形面积和周长;

import java.util.Scanner;

//长方形类文件
public class Rectangle {
      private double a,b; //字段:保存长度和宽度
      private double Area() //方法:计算面积
      {
        return a*b;
      }
      private double Len()  //计算周长
      {
        return 2*(a+b);
      }
      public void Input() {
        Scanner sc=new Scanner(System.in);
        System.out.println("请输入长和宽:");
        a=sc.nextDouble();
        b=sc.nextDouble();
      }
      public void Output() {
        System.out.println(Area()+","+Len());
      }
}

package 计算长方形面积和周长;
//主类文件
public class RectangleTest {
    //将主函数main()定义在类中
  public static void main(String[] args) {
  //java需要动态创建对象
    Rectangle obj=new Rectangle();
    obj.Input();//输入长宽
        obj.Output();//显示结果
  }

}

package 鱼塘造价;

public class CirclePool {   //圆形水池类
   public double r; //半径
   public double CircleCost() //计算造价
{
     return 3.14*r*r*10;
   }
}

package 鱼塘造价;

//长方形养鱼池类
public class RectPool{ //长方形养鱼池类
  public double a,b;//长宽
  public double RectCost()  //计算造价
{
    return a*b*10;
  }
}
//测算养鱼池工程总造价
package 鱼塘造价;

import java.util.Scanner;

//主类+方法
public class Pool {   //主类
    
  public static void main(String[] args) {
    Scanner sc=new Scanner(System.in);
    double totalCost=0; //保存总造价的变量
        //处理长方形养鱼池
    RectPool rObj;    //定义引用
    rObj=new RectPool();  //创建长方形鱼池对象
    System.out.println("请输入长方形鱼池的长和宽:");
    rObj.a=sc.nextDouble();  //输入长宽值
    rObj.b=sc.nextDouble();  
    totalCost+=rObj.RectCost();//汇总造价
    //处理清水池和污水池
    CirclePool cObj1,cObj2;
    cObj1=new CirclePool(); //创建清水池对象
    cObj2=new CirclePool(); //创建污水池对象
    System.out.println("请输入清水池和污水池的半径:");
    cObj1.r=sc.nextDouble();//输入清水池半径
    cObj2.r=sc.nextDouble();//输入污水池半径
    totalCost+=cObj1.CircleCost();//汇总造价
    totalCost+=cObj1.CircleCost();//汇总造价
        //显示总造价
    System.out.println(totalCost);
  }

}

标签：java,double,System,学习,造价,sc,new,public
来源： https://www.cnblogs.com/dss-99/p/14016775.html