库存程序的Java代码第3部分不会编译

Question

纠正了以前的错误，现在出现了这个错误。

C:\Documents and Settings\AdminUser\My Documents\InventoryPart3.java:93: invalid method declaration; return type required
public Television(int ItemNumber, String ProductName, int UnitsStock, double UnitPrice, String mfgName) {
       ^
1 error

Tool completed with exit code 1

 class Television { //class name and attributes

    private String ItemNumber; //item # of product
    private String ProductName; //product name
    private double UnitsStock; //# of units in stock
    private double UnitPrice; //Price per unit
    private String SerialNumber; //serial number of product
    private double InventoryValue; //The dollar value of the inventory in stock

//constructor

 public Television (String item, String product, double units, double price, String serial) {

    ItemNumber = item;
    ProductName = product;
    UnitsStock = units;
    UnitPrice = price;
    SerialNumber = serial;

} //end constructor

///getter and setter methods for Television

public void setItemNumber (String item) { //setter for item number
    this.ItemNumber = item;
} //end setter item number

public String getItemNumber() { //getter for item number
    return ItemNumber;
} //end getter item number

public void setProductName (String product) { //setter for product name
    this.ProductName = product;
} //end setter product name

public String getProductName() { //getter for product name
    return ProductName;
} //end getter product name

public void setUnitsStock (double units) { //setter for units in stock
    this.UnitsStock = units;
} //end setter units in stock

public double getUnitsStock() { //getter for units in stock
    return UnitsStock;
} //end getter units in stock

public void setUnitPrice (double price) { //setter for unit price
    this.UnitPrice = price;
} //end setter unit price

public double getUnitPrice() { //getter for unit price
    return UnitPrice;
} //end getter for unit price

public void setSerialNumber (String serial) { //setter for serial number
    this.SerialNumber = serial;
}//end setter for serial number

public String getSerialNumber() { //getter for serial number
    return SerialNumber;
}//end getter for serial number



//calculate individual product inventory value

public double getInventoryValue(){
    return UnitsStock * UnitPrice;

}//end calculate individual product inventory value


//calculate total inventory value
public double calculateInventory(){
    return UnitPrice * UnitsStock;
}//end calculate total inventory value

///end getter and setter methods for Laptop

} //end class Television

class Manufacturer extends Television {
private String manufacturerName;

//constructor

public Television(int ItemNumber, String ProductName, int UnitsStock, double UnitPrice, String mfgName) {
    super(ItemNumber, ProductName, UnitsStock, UnitPrice, ManufacturerName);

    this.manufacturerName = mfgName;

}//end constructor

//getter and setter for class Manufacturer

public void setmanufacturerName(String mfgName) {
    this.manufacturerName = mfgName;
}

public String getmanufacturerName() {
    return manufacturerName;
}

//end getter and setter for class Manufacturer

//calculate total inventory value

public double calculateInventory(){
    return ((UnitPrice * UnitsStock));

}//end calculate total inventory value

//calculate restocking fee method

public double getcalculateRestockFee() {
    return getInventoryValue();

    }//end calculate restocking fee method

}//end class Manufacturer

Answer 1

所以有两个错误。第一个出现在文件InventoryPart3.java的第93行。在这一行中，您将找到代码：

 super(ItemNumber, ProductName, UnitsStock, UnitPrice);

这实际上是对电视类的构造函数的调用。然而，the类的构造函数接受5个参数: String、String、double、double、String，但您只传递了4个参数。

第二个错误发生在同一文件的第120行。在这种情况下，您似乎在调用一个方法，但是省略了括号。也就是说，守则应是：

   getInventoryValue()

Answer 2

在电视类中，您试图从制造商类调用的超级电视的构造函数并不存在。请查看超级()调用中的参数和the构造函数中的实际参数。getInventoryValue函数不在an class.Hence中，它正在为super.getInventory调用抛出一个错误

Answer 3

第一个错误与to构造函数有关。电视构造函数采用5个参数，类型为String、String、double、double、String。在制造商类中，使用int、string、int和double调用超类构造函数。在子类中，超级()构造函数调用必须匹配基类( the )中的一个构造函数。

对于第二个错误，对getInventoryValue的调用有一个语法错误。要在Java中调用方法，必须在方法的名称后面加上括号：

return super.getInventoryValue() * 0.10;

注意，在本例中，super.部分是可选的。getInventoryMethod()存在于超类中，不属于私有类，因此可以从子类中调用它，如下所示：

return getInventoryValue() * 0.10;