类C++测试

Question

我试图解决C++中的问题，但因为我是一个begginer我不知道该怎么做！ 问题是，如果你能帮我:) :)：

通过使用下面的C++代码创建关于类“汽车”&“卡车”正确的构造函数。每个功能必须将合适的参数传递给父级车辆。另外，功能汽车在创建对象时应该初始化乘客。卡车类应在创建对象时初始化装载限制。

对象与汽车（）和卡车（）语句将如下：

车OB（人次，轮毂，范围）;

truck ob（loadlimit，wheels，range）;

#include <iostream> 
using namespace std; 
    class vehicle{   
      int num_wheels;  
      int range; 
      public: 
       vehicle(int w, int r){num_wheels = w; range = r;} 
       void showv(){ 
        cout << "Wheels: " << num_wheels << endl; 
        cout << "Range: " << range << endl; 
       } 
    }; 

    class car : public vehicle { 
      int passengers; 
      public: 
       void show(){ 
        void showv();  
        cout << "Passengers: " << passengers << endl;  
       }   
    }; 

    class truck : public vehicle {   
      int loadlimit;   
      public:   
       void show(){  
        void showv();   
        cout << "Loadlimit: " << loadlimit << endl;   
       }   
    }; 

    int main(){   
     car c(5, 4, 500);   
     truck t(3000, 12, 1200);   
     cout << "Car: " << endl;   
     c.show();   
     cout << "Truck: " << endl;   
     t.show();   
     return 0;   
    } 

Answer 1

类Car和Truck不具有采取必要参数的构造函数，并传递给基类的构造函数。他们应该是这样的：

class car : public vehicle { 

    int passengers; 

public: 

    car(int w,int r,int p): vehicle(w,r), passengers(p){} 
    void show(){ 

     void showv(); 

     cout << "Passengers: " << passengers << endl; 

    } 
}; 

class truck : public vehicle { 

     int loadlimit; 

     public: 

      truck(int r, int w, int l):vehicle(r,w),loadlimit(l){} 

      void show(){ 

       void showv(); 

       cout << "Loadlimit: " << loadlimit << endl; 

      } 

}; 

Answer 2

简单的解决方案，

car::car(int w,int r,int p) 
{ 
    passengers = p; 
    vehicle::vehicle(w,r); 
} 

Answer 3

基地成员初始化

Car构造：

car(int a, int b, int c) : vehicle(a,b),passengers(c){}; //initialiser list 

Truck构造：

truck(int g, int h, int j):vehicle(g,h),loadlimit(j){} 

Answer 4

你需要一个承包商添加到汽车和卡车

class car : public vehicle { 

      int passengers; 
      public: 
      car(int p) : vehicle(int w, int r) // Call the superclass constructor in the subclass' 
      { 
       passengers = p; 
      } 

      void show() 
      { 
       showv();  
       cout << "Passengers: " << passengers << endl;  
      }   
     }; 

卡车