java - Classname.Variable 使用 Classname 作为变量

Question

根据另一个类中给定的输入，此类必须从要在其中找到该变量的 4 个类之一检索变量。例如。如果输入是 s，则此类要查找的变量可在 Sumup.counter 中找到，而当输入是 a 时，它需要的变量可以在 Abstract.counter 等中找到，以便填充数组。在这 4 个不同的类别之一中，它必须选取 5 个不同的变量。因此，为了避免大量额外的编程，我想用变量替换这些类名 Sumup 和 Abstract 。因此它必须看起来像 Variable.counter、Variable.part1 等。其中 Variable 可以是 Sumup 或 摘要(或乘或除)。

有人建议如何做到这一点吗？

public class Erroranalysis {

    public static int[][] wrongcalculations = new int[5][Numberofcalculations.numcalc]; 

    static int runner = 0;
    static String routine;

    public static void main(String[] args) 
    {
        switch (kindofcalculation.choice) 
        {
         case "s":
             routine = "Sumup";
         break; 

         case "a":
             routine = "Abstract";
         break; 

         case "m":
             routine = "Multiply";
         break;     

         case "d":
             routine = "Divide";
         break; 
         }   

         if (routine.counter <= Numberofcalcluations.numcalc)
         {

             wrongcalculations[0][runner] = routine.counter;
             wrongcalculations[1][runner] = routine.part1;
             wrongcalculations[2][runner] = routine.part2;
             wrongcalculations[3][runner] = routine.result;
             wrongcalculations[4][runner] = routine.answer;


             runner++;
         }
    }
}

Answer 1

您可以选择一个基本抽象类并创建该类的数组:

class Base{
  public int counter = 0;
}
class Sumup extends Base{
}
class Abstract extends Base{
}


public class Erroranalysis {

    public static int[][] wrongcalculations = new int[5][Numberofcalculations.numcalc]; 

    static int runner = 0;
    static Base routine;
    static Sumup sumup;
    static Abstract abs;

    public static void main(String[] args) 
    {
        sumup = new Sumup();
        abs = new Abstract();

        // possibly, this part won't be in main, but in some for loop of another method
        switch (kindofcalculation.choice) 
        {
         case "s":
             routine = sumup;

         case "a":
             routine = abs;

         }   

         if (routine.counter <= Numberofcalcluations.numcalc)
         {

             wrongcalculations[0][runner] = routine.counter;
             wrongcalculations[1][runner] = routine.part1;
             wrongcalculations[2][runner] = routine.part2;
             wrongcalculations[3][runner] = routine.result;
             wrongcalculations[4][runner] = routine.answer;

             runner++;
         }
    }
}