java - 如何比较两个双数并找到较小的

Question

此类包含矩形列表，我需要找到面积最小的矩形。

我发现需要按面积比较矩形，但它具有 double 。 我知道我的比较记得最后一个，但是我们如何在这里进行此检查？

代码:

   /**
    * Gets the Rectangle with the smallest area
    * @return the rectangle with the smallest area or null if
    * there are no rectangles
    */
   public Rectangle smallestArea()
   {        
       if (list.size() == 0) return null;

       Rectangle smallest = list.get(0);           
       double smallestArea = smallest.getWidth() * smallest.getHeight();

       for (int i = 1; i < list.size(); i++) {
           Rectangle next = list.get(i);
           double nextArea = next.getWidth() * next.getHeight();

           if ((nextArea - smallestArea) < 0) smallest = next;             
       }

       return smallest;
   }

如何解决这个问题？

Answer 1

您还应该更新 smallestArea 局部变量(代码中多一行):

   public Rectangle smallestArea()
   {        
       if (list.size() == 0) return null;

       Rectangle smallest = list.get(0);           
       double smallestArea = smallest.getWidth() * smallest.getHeight();

       for (int i = 1; i < list.size(); i++) {
           Rectangle next = list.get(i);
           double nextArea = next.getWidth() * next.getHeight();

           if ((nextArea - smallestArea) < 0) { 
             smallest = next;         // <- Whenever you've updated smallest           
             smallestArea = nextArea; // <- Do not forget updating the smallestArea as well
           }  
       }

       return smallest;
   }