Change size of array filled with class objects at runtime c++

Question

I have a class that has to store the weight of the animal and it's type. Depending on what the user wants, there can be as many instances of that class created at runtime. My problem is with not being able to properly declare a dynamic array that can resize itself once the entire array has been filled with objects.

class FarmAnimal
{

private:
    short int type;
    int weight;
    double WaterConsumed;



public:
    static int NumberOfSheep;
    static int NumberOfHorse;
    static int NumberOfCow ;
    static double TotalWaterUsed;

    FarmAnimal(int type, int weight)
    {
        this->type = type;
        this->weight = weight;
    }
        int CalculateWaterConsumption(void);
        void ReturnFarmInfo(int& NumberOfSheep, int& NumberOfHorse, int& NumberOfCow, int& TotalWaterUsed)
};

int main()
{
...
short int k;
...
do
{
...

FarmAnimal animal[k](TypeOfAnimal, weight);
        k++;
        cout << "Would you like to add another animal to your farm?\n Press\"0\" to exit and anything else to continue" << endl;
        cin >> ExitButton;
    } while (ExitButton != 0)

and the end of the program


            animal[0].ReturnFarmInfo(NumberOfSheep, NumberOfHorse, NumberOfCow, TotalWaterUsed)

    cout << " Your farm is made up of :" << NumberOfSheep << " sheeps " << NumberOfHorse" horses " << NumberOfCow << " cows " << endl;
    cout << "The total water consumption on your farm per day is: " << TotalWaterUsed << endl;
}

Some compilers allow variable length arrays, portable C++ does not. Use std::vector instead. — Ron
– Ron, Commented Sep 6, 2019 at 9:03
C++ doesn't have variable-length arrays. Use std::vector instead. — Some programmer dude
– Some programmer dude, Commented Sep 6, 2019 at 9:04

IIRistoII · Accepted Answer · 2019-09-06 09:52:40Z

3

Array cannot change size in C++. You need to use a dynamic container such as std::vector. A documentation of the vector class can be found here.

std::vector<FarmAnimal> animals;

bool done = false;
while (!done)
{
    animals.push_back(FarmAnimal(TypeOfAnimal, weight));
    cout << "Would you like to add another animal to your farm?\n Press\"0\" to exit and anything else to continue" << endl;
    cin >> ExitButton;
    done = (ExitButton != 0);
}

answered Sep 6, 2019 at 9:52

IIRistoII

3301 silver badge7 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Ana · Accepted Answer · 2019-09-06 09:15:54Z

3

Use the std::vector from the standard library and the method push_back() to add new elements

http://www.cplusplus.com/reference/vector/vector/

answered Sep 6, 2019 at 9:15

Ana

1771 silver badge13 bronze badges

Comments

Homeless0alien · Accepted Answer · 2019-09-06 09:11:28Z

0

As mentioned in the comments by Some programmer dude and Ron, variable-length arrays are not supported in C++ by default. The std::vector class is a useful tool should you require them.

Some basic info about vectors: http://www.cplusplus.com/reference/vector/vector/

answered Sep 6, 2019 at 9:11

Homeless0alien

112 bronze badges

Collectives™ on Stack Overflow

Change size of array filled with class objects at runtime c++

3 Answers 3

Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related