java - 未定义的构造函数错误

Question

我正在尝试为汽车经销商实现一个系统，但是当我尝试在派生类中实例化我的 Car 类时，我收到错误消息

Multiple markers at this line
- The constructor Car(String, int, String, String, double, double) is 
 undefined

这是父类 Car:

package Number3;

public class Car {

private String plateNum;
private int year;
private String make;
private String model;
protected double costPrice;
protected double sellingPrice;

public Car()
{
    plateNum = "";
    year = 1990;
    make = "";
    model = "";
    costPrice = 0.0;
    sellingPrice = 0.0;
}

public Car(String plateNum,int year,String make,String model,double costPrice,double sellingPrice)
{
    this.plateNum = plateNum;
    this.year = year;
    this.make = make;
    this.model = model;
    this.costPrice = costPrice;
    this.sellingPrice = sellingPrice;
}

public double getCostPrice()
{
    return costPrice;
}

public double computeSellPrice()
{
    sellingPrice = costPrice;
    return sellingPrice;
}

public void displayCarDetails()
{
    System.out.println("Plate number: "+plateNum);
    System.out.println("Year: "+year);
    System.out.println("Make: "+make);
    System.out.println("Cost price: "+costPrice);
    System.out.println("Selling price: "+sellingPrice);
}

}

和子类newCar:

package Number3;

public class newCar extends Car{

private double tax;

public newCar(String plateNum,int year, String make, double costPrice, double sellingPrice, double tax)
{
    super(plateNum,year,make,costPrice,sellingPrice); //where the error is found
    this.tax = (25/100);
}

public double computeSellPrice()
{
    sellingPrice = costPrice + (costPrice * tax);
    return sellingPrice;
}

public void displayCarDetails()
{
    super.displayCarDetails();
}
}

如有任何帮助，我们将不胜感激。

Answer 1

您的 Car 构造函数的签名与派生类中的签名不匹配。

在您的 Car 类中，这是构造函数:

public Car(String plateNum,int year,
      String make,String model,double costPrice,double sellingPrice) {
        ...
  }

它是字符串，int，字符串，字符串， double ， double )

在派生类中:

你有:

super(plateNum,year,make,costPrice,sellingPrice)

这是int、int、String、double、double

更改 newCar 类中对 Super 的调用参数，以匹配 Car 类的构造函数。也就是说，在您的 newCar 类中，行

super(plateNum,year,make,costPrice,sellingPrice)

应该是:

super(plateNum, year,
      make, model, costPrice, sellingPrice)