没有适当的默认构造函数可用错误 [英] no appropriate default constructor available error

问题描述

这里是我的代码：

class package
{
protected:
    string name;
    string city;
    string state;
    int zip;
    double weight;
    double costPerOunce;

public:

    package::package(string Name, string City, string State, int Zip, double Weight, double CostPerOunce):
      name(Name), city(City), state(State),
      zip(Zip), weight(Weight), costPerOunce(CostPerOunce)
      {

      }
      double calculateCost()
    {
        return (weight * costPerOunce);
    }

};
class twoDayPackage: public package
{
protected:
    double flatFee;
public:
    twoDayPackage::twoDayPackage(double FlatFee):
      flatFee(FlatFee)
      {

      }
    double calculateCost()
    {
        return (weight * costPerOunce) + flatFee;

    }
};
int main()
{


    system ("pause");
    return 0;
}

我试图运行这个代码，我得到的错误如下：
错误C2512：'package'：没有适当的默认构造函数

i try to run this code and the error i get is as follows: error C2512: 'package' : no appropriate default constructor available

错误与基类构造函数的继承有关，但我不知道为什么代码不运行。请帮助我。

the error has something to do with inheritance of the base class constructor but i don't know exactly why the code isn't running. please help me.

推荐答案

twoDayPackage 的构造函数将首先创建 package ，然后构造 flatFee 。因为你不告诉它如何做，它寻找一个默认的方式来构造 package 。

The constructor for twoDayPackage will first create package, before constructing flatFee. As you don't tell it how to do that, it looks for a default way of constructing package.

当你构造 twoDayPackage 时，你需要给它构建基础的包所需的一切。或者让它确定要传递给包构造函数的值。

When you construct twoDayPackage you need to give it everything it needs to construct the underlying package. Either that, or have it determine values to pass to the package constructor.

传递所需的参数看起来像这个：

Passing in the required parameters looks like this:

class twoDayPackage {
public:
    twoDayPackage(string Name, string City, string State, int Zip, double Weight, double CostPerOunce, double flatFee) :
    package(Name, City, State, Zip, Weight, CostPerOunce),
    flatFee(flatFee) {
    }
    //..
};

这篇关于没有适当的默认构造函数可用错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！