java - 为什么数组索引没有被交换？

Question

我正在尝试交换数组位置，但它不起作用。无论我做什么，我都无法让它们交换，我知道这与我编写 if 语句的方式有关。

这是主代码:

  Comparable[] computerSizes = new Comparable[3];

   int a = computerSizes.length - 1;



   computerSizes[0] = new Desktop("i5","Desktop",4,1024,250); 
   computerSizes[1] = new Desktop("i3","Desktop",6,512,350); 
   computerSizes[2] = new Laptop(15.6,"i3","Laptop",4,0,750); 

   for (int i = 0; i < a;i++) {

     if(computerSizes[i].compareTo(computerSizes[i+1]) == 1){
          computerSizes[i] = computerSizes[i+1];
          computerSizes[i+1] = computerSizes[i];
        }//end if
     System.out.println(computerSizes[i]);
    }//end for

以下是相关的compareTo方法代码:

 public int compareTo(Comparable c)
{   
    Computer a = (Computer)c;


     if (this.cost == a.cost)
        return 0;
     else if (this.cost > a.cost)
        return 1;
     else
        return -1;



}

0 处的索引大于 1 处的索引，但为了澄清起见，我将包括相关公式:

cost = 150 + 6.50 * super.ram + 0.15 * super.hdd + 0.48 * super.vRam;

桌面(处理器，类型，RAM，VRAM，HDD SPACE):这就是参数的含义。

Answer 1

线条

computerSizes[i] = computerSizes[i+1];
computerSizes[i+1] = computerSizes[i];

不要做你期望的事情。它首先将 computerSizes[i+1] 的值分配给 computerSizes[i]。那一刻，两人是平等的。然后将 computerSizes[i] 的值分配给 computerSizes[i+1]。最终，两者将相等。

为了交换值，请使用时间变量:

Comparable temp = computerSizes[i];
computerSizes[i] = computerSizes[i+1];
computerSizes[i+1] = temp;