Question

// Please follow all the instructions

Each of the class declarations and/or member function definitions below has syntax error(s).

Find every error. All errors with explanation and fix the code.

* Hint: You may use compiler to help you find the error. However, you need to set up the program correctly and to point out the true cause of the syntax error. Because the compiler messages are convoluted, due to the convoluted nature of language dependencies.

54.

class Truck, public : Vehicle, protected {
private:
    double cargoWeight;
public:
    Truck();
    ~Truck();
}; 

55.

class SnowMobile : Vehicle {
protected: 
    int horsePower;
    double weight;
public:
    SnowMobile(int h, double w), Vehicle(h)
    { horsePower = h; }
    ~SnowMobile();
};

56.

class Table : public Furniture {
protected:
    int numSeats;
public:
    Table(int n) : Furniture(numSeats)
    { numSeats = n; }
    ~Table();
};

57.

class Tank : public Cylinder {
private:
    int fuelType;
    double gallons;
public:
    Tank();
    ~Tank();
    void setContents(double);
    void setContents(double);

58.

class Three : public Two : public One {
protected:
    int x;
public:
    Three(int a, int b, int c), Two(b), Three(c)
    { x = a; }
    ~Three();
}; 

Answer 1

54) correct answer:

    class Truck : public Vehicle{

    private:

        double cargoWeight;

    public:

        Truck();

        ~Truck();

    };

solution:

• We can write directly Inheritance colon(:) after the class name
• Base class can be written directly after the base class access specification which should be either public or protected but we cannot used both for a single base class
• There is a Comma exists if we used the multiple inheritance. Multiple inheritance is not used here so we can eliminate it.

55)correct answer:

class SnowMobile : public Vehicle
{
protected:
int horsePower;
double weight;
public:
SnowMobile(int h, double w):vehicle(h)
{
horsePower = h;
}
~SnowMobile();
};
solution:

• Base class can be written directly after the base class access specification which should be either public or protected but there is no access specifier here so I can add public access specifier.
• Here, Base class Constructor can called inside Derived class so that colon can write before the base class name.

56) correct answer:

class Table : public Furniture
{
protected:
int numSeats;
public:
Table(int n) : Furniture(n)
{
numSeats = n;
}
~Table();
};
solution:

Here, Base class Constructor can called inside Derived class. wrong parameter to the base class constructor ,it should be n instead of numseats

57)correct answer:
class Tank : public Cylinder{
private:
int fuelType;
double gallons;
public:
Tank();
~Tank();
void setContents(double);
void setContents(int);
void setContents(int,double);
};
solution: From the above code, there is a duplication of setContents function so we can eliminate the duplication here.

58) correct answer:

class Three : public Two, public One
{
protected:
int x;
public:
Three(int a, int b, int c): Two(b), Three(c)
{
x = a;
}
~Three();
};
solution:

• Here multiple inheritance is used in above code so in this case, 1st class Two constructor will be executed, then class One constructor and then class Three constructor. Here, comma is missing between two base class constructors.
• We have created three classes One, Two,Three. All of these classes have parameterized constructors, we could access constructor of parent class by using a scope resolution operator (‘:’).