c++ - C++ 中的类和对象......需要一些额外的固定装置

Question

我写了一个类和对象程序，它给了我一些我无法避免的错误。这里有一些我无法解决的错误，它们在 Main.cpp 中找到以下错误....

  Car car1("Ford", "Crown Victoria", 1997);
   Car car2("Chevrolet", "Camaro");
   Car car3("Hyundai", "Sonata", -15);
126 IntelliSense: no instance of constructor "Car::Car" matches the argument list
        argument types are: (const char [5], const char [15], int)

和

   car1.SetValue("Flinstones", "Rock Car", -2100);
   car3.SetValue("Toyota", "Camry", 2005);


132 IntelliSense: a reference of type "std::string &" (not const-qualified) cannot be initialized with a value of type "const char [6]"

这是我的代码

// -----------------------Car.h-----------------------
#include <iostream>
#include <string>

class Car{
public:
    Car(string &make, string &model, int year=2015);        // constructor with three parameters
    string GetMake();
    string GetModel();
    int GetYear();
    int GetSpeed();

    bool SetValue(string &make, string &model, int year);   // set values from parameters
    bool Accelerate(char a);
    bool Brake(char b);
    void Display();                                                 // displays the output

private:
    string automake;
    string automodel;
    int autospeed;
    int autoyear;
};

// -----------------------------Car.cpp---------------------------
// The class definition for Car.
#include <iostream>
#include "Car.h"
#include <string>

using namespace std;

Car::Car(string &make, string &model, int year)
{
    automake = make;
    automodel = model;
    autospeed = 0;

    if(year < 0)
        year = 2015;
    else
        autoyear = year;
}

string Car::GetMake()
{
    return automake;
}

string Car::GetModel()
{
    return automodel;
}

int Car::GetYear()
{
    return autoyear;
}

int Car::GetSpeed()
{
    return autospeed;
}

bool Car::SetValue(string &make, string &model, int year)
{
    if(year < 0)
    {
        automake = make;
        automodel = model;
        autoyear = year;
        return true;
    }
    else
        return false;
}

void Car::Display()
{
    //cout <<"Your car is a " << autoyear << automodel << automake << endl;
    //cout <<"And it is currently going " << autospeed << " MPH." << endl;
}

bool Car::Accelerate(char a)
{
    if((a=='H')||(a=='h')||(a=='M')||(a=='m')||(a=='L')||(a=='l'))
    {
        if((a=='H')||(a=='h'))
            autospeed += 10;
        if((a=='M')||(a=='m'))
            autospeed += 5;
        if((a=='L')||(a=='l'))
            autospeed += 1;
        return true;
    }
    else
        return false;
}

bool Car::Brake(char b)
{
    if((b=='H')||(b=='h')||(b=='M')||(b=='m')||(b=='L')||(b=='l'))
    {
        if((b=='H'||b=='h' && autospeed > 10))
            autospeed = 10;
        if((b=='M'||b=='m' && autospeed > 5))
            autospeed = 5;
        if((b=='L'||b=='l' && autospeed > 1))
            autospeed = 1;
        return true;
    }
    else
        return false;
}

// -------------Main.cpp--------------------

// Driver routine to test the functions of the Car class

#include <iostream>
#include <string>
#include "Car.h"
#include "Car.cpp"

using namespace std;

int main()
{
   Car car1("Ford", "Crown Victoria", 1997);
   Car car2("Chevrolet", "Camaro");
   Car car3("Hyundai", "Sonata", -15);

   cout << "\n*** Displaying each car's stats\n";
   cout << "Car1:\n";
   car1.Display();
   cout << "\nCar2:\n";
   car2.Display();
   cout << "\nCar3:\n";
   car3.Display();

   cout << "\n*** Accelerating car 3 several times:\n";

   car3.Accelerate('h');        // accelerate hard
   cout << "Car3 speed: " << car3.GetSpeed() << '\n';

   car3.Accelerate('M');        // accelerate medium
   cout << "Car3 speed: " << car3.GetSpeed() << '\n';

   car3.Accelerate('L');        // accelerate low
   cout << "Car3 speed: " << car3.GetSpeed() << '\n';

   car3.Accelerate('L');        // accelerate low
   cout << "Car3 speed: " << car3.GetSpeed() << '\n';

   car3.Accelerate('Z');        // accelerate with invalid level
   cout << "Car3 speed: " << car3.GetSpeed() << '\n';

   cout << "\n*** Resetting car make/models\n";
   car1.SetValue("Flinstones", "Rock Car", -2100);
   car3.SetValue("Toyota", "Camry", 2005);

   cout << "Car1:\n";
   car1.Display();
   cout << "\nCar3:\n";
   car3.Display();

   cout << "\n*** Decelerating car3\n";
   car3.Brake('m');
   cout << "Car3 speed: " << car3.GetSpeed() << '\n';
   car3.Brake('L');
   cout << "Car3 speed: " << car3.GetSpeed() << '\n';
   car3.Brake('l');
   cout << "Car3 speed: " << car3.GetSpeed() << '\n';
   car3.Brake('M');
   cout << "Car3 speed: " << car3.GetSpeed() << '\n';
   car3.Brake('A');
   cout << "Car3 speed: " << car3.GetSpeed() << '\n';
   car3.Brake('H');
   cout << "Car3 speed: " << car3.GetSpeed() << '\n';

   cout << "\n*** Calling accessors\n";
   cout << "Car1:\n";
   cout << "  Make:  " << car1.GetMake() << '\n'
        << "  Model: " << car1.GetModel() << '\n'
        << "  Year:  " << car1.GetYear() << '\n';

   cout << "Car2:\n";
   cout << "  Make:  " << car2.GetMake() << '\n'
        << "  Model: " << car2.GetModel() << '\n'
        << "  Year:  " << car2.GetYear() << '\n';

   cout << "Car1:\n";
   cout << "  Make:  " << car3.GetMake() << '\n'
        << "  Model: " << car3.GetModel() << '\n'
        << "  Year:  " << car3.GetYear() << '\n';

}

Answer 1

如错误所述，您需要为 const 引用提供构造函数:

Car(const string &make, const string &model, int year=2015);