In 和 Double 到字符串

Question

给定骨架程序，我无法弄清楚它是如何工作的......

必须使用这种格式...

无法让它从参数行中读取参数并且不知道如何使用开关转到不同的方法...

Program:
        //**********************************************************************************
    //Purpose:  Compute personal income taxes.
    //
    //Input:    Name, status, and annual income
    //
    //Output:   name, status, annual income, and tax due
    //
    //    Expand and complete the documentation section
    //
    //**********************************************************************************
    public class MyIncomeTax5{
   //Declarations
   public static String name;
   public static String status;
   public static double statusName;
   public static double annualIncome;
   public static double taxDue;

   //*******************************************************************************
   // Have a documentation section in front of each method
   //
   //*******************************************************************************
   public static void main (String [] args){
      readArguments(args);
      computeTax();
      //printOutput();
   }

   public static void readArguments(String [] args){

      //Assign arguments to name, status, and annual income
      /*System.out.println ("readArguments to be implemented");
      System.out.println ("in readArguments assign arguments to name, status, and annual income");*/
      name = args[0];
      status = args[1];
      //annualIncome = args[2];

   }

   public static void computeTax(){

      //Use a switch statement to invoke the appropriate method
      //Based on the value in status and assign a value to statusName.

      switch (status){
      case "0": computeSingleFilers();

               break;
      case "1":

               break;
      case "2":

               break;
      case "3":

               break;
      default: 
      }


  }

  public static void computeSingleFilers(){ 

  }

  public static void computeMarriedFilingJointly(){

  }

   public static void computeMarriedFilingSeparately(){

  }

  public static void computeHeadOfHousehold(){

  }

  /*public static void printOutput(){

   displayHeader();
   displayFooter();
  }

   public static void displayHeader(){
   System.out.println ("********************************************************************");
   System.out.println ("**                                                                **");
   System.out.println ("**        Estimating 2016 Personal Federal Income Tax             **");
   System.out.println ("**                                                                **");
   System.out.println ("**        CS1301                                                  **");
   System.out.println ("**                                                                **");
   System.out.println ("**        2/10/2017                                               **");
   System.out.println ("**                                                                **");
   System.out.println ("********************************************************************");
   System.out.printf ("%-25s%-25s", "Name:", name);
   System.out.printf ("%-25s%-25s", "Status:", statusName);
   System.out.printf ("%-25s%-25s", "Name:", name);
   System.out.printf ("%-28s%-25s", "Annual Income:", annualIncome);
   System.out.printf ("%-28s%-25s", "2016 estimated tax due:", taxDue);



   }

    public static void displayFooter(){
    System.out.println ("********************************************************************");
    System.out.println ("**                                                                **");
    System.out.println ("**        It is needed but not fun to pay taxes                   **");
    System.out.println ("**                                                                **");
    System.out.println ("**        Have a good day                                         **");
    System.out.println ("**                                                                **");
    System.out.println ("********************************************************************");
    */




    }

Answer 1

你的声明应该是：

   //Declarations
   public static String name;
   public static int status;
   public static double statusName;
   public static double annualIncome;
   public static double taxDue;

像这样解析它：

    public static void readArguments(String [] args){
       name = args[0];
       status = Integer.parseInt(args[1]);
       annualIncome = Double.parseDouble(args[2]);
   }

然后通过删除双引号将您的 switch 语句大小写更改为 int。

cases "0":

到

cases 0:

args[1] 和args[2] 字面意思是来自String[] 的数组，所以它实际上是返回一个字符串值，所以你需要解析它以便转换它的类型数据，请参阅上面我如何将 String 解析为 int 和 double 的代码。