java - 在方法中传递 boolean 参数，但方法 boolean 变量仍然未使用

Question

这里有点Java菜鸟。因此，我在处理类中调用一个名为 ageRestrProcessor() 的方法，该方法采用 boolean 值 ageValidationStatus 参数。 Processing 类有一个 boolean 变量 ageNotValidated 已初始化为 true。所以现在，我尝试将 ageNotValidated 变量作为参数传递到 ageRestrProcessor() 方法中，然后在该方法中尝试将 boolean 值更改为 false 。但是，在方法本身中，它表示 boolean 变量ageValidationStatus未使用。显然， boolean 值永远不会改变。从表面上看，这似乎应该可行，但我无法弄清楚问题是什么。预先感谢您的回复。

//ItemProcessors class

public class ItemsProcessors {
  void ageRestrProcessor(int keyNum, String itemNameFromDB, double itemUnitPriceFromDB, boolean ageValidationStatus, boolean ageValidator, String itemUnit, Map<Integer, Object[]> map){
    double ageRstrItemPrice = bp.roundUpToTwoDecimals(itemUnitPriceFromDB);
    String dollarAgeRestPrice = bp.addDollarFormat(ageRstrItemPrice);

    if (ageValidator){
        System.out.println("\tAge Validation Successful");
        System.out.println("\tTotal Price: " + dollarAgeRestPrice);
        map.put(keyNum, new Object[] {itemNameFromDB, itemUnitPriceFromDB, itemUnit, ageRstrItemPrice, dollarAgeRestPrice});

        //Here, the compiler is telling me that ageNotValidated variable is never used.
        ageValidationStatus = false;
    }
    else {
        System.out.println("\tShopper is underage. Item not added");
    }
  }
}

//I'm calling the ageRestrProcessor method into this Processing class

public class Processing extends OrderData {
   private Map<Integer, Object[]> itemMap = new HashMap<Integer, Object[]>();
   BasePage bp = new BasePage();
   private Exceptions xcep = new Exceptions();
   private ItemsProcessors ip = new ItemsProcessors();
   public boolean ageNotValidated = true;

   public void itemsProcessor(XSSFSheet itemSheet){
      if (xcep.isAgeRestricted(itemSheet, rowNum) && ageNotValidated){
         String ageEntered = bp.getStringFromScanner("\tEnter DOB in 'mm-dd-yyyy' format: ");
         boolean isAgeValid = xcep.ageValidator(ageEntered);

         //I'm trying to pass the ageNotValidated variable into the method here.
         ip.ageRestrProcessor(keynum++, itemNameFromDB, itemUnitPriceFromDB, ageNotValidated, isAgeValid, itemUnit, itemMap);
      }
    }
}

Answer 1

ageValidationStatus 是在 ageRestrProcessor 方法内部创建的，不能在此方法之外使用(local 变量)，并且不会在该方法中的其他任何地方使用当前方法也是如此

所以这是编译器发出的警告，以提高代码质量，当它在其他地方没有用时进行不必要的赋值

<小时/>

使ageRestrProcessor返回boolean标志并相应地使用值

  boolean ageRestrProcessor(int keyNum, String itemNameFromDB, double itemUnitPriceFromDB, boolean ageValidationStatus, boolean ageValidator, String itemUnit, Map<Integer, Object[]> map){
         //..code
         // you can remove  boolean ageValidationStatus from method signature
    if (ageValidator){
         //..code
         return false;
    }
    else {
        System.out.println("\tShopper is underage. Item not added");
        return true;
    }
  }

和

ageNotValidated = ip.ageRestrProcessor(keynum++,....;