C Modify an array passed by parametres-CodePudding

I'm new at c and I'm having some difficulty on passing an array to a function.

I want to create an array of type Tableau (it initialize automatically at 4) and pass that array to another function, so passing distanceReste to calculReste.

I want to be able to change the array inside the other function, so for example, I want to add 1,2 and 3 and make the changes take place even after I leave that function.

So in my code, I would create the array, send it to calculReste, put the result of calculReste is reste and keep the changes to my array distanceReste I made so then I can use it in the function calculDepartReste (I didn't put it in the code).

Here's my code:

 Tableau<double> distanceReste[3];
    Tableau<double> reste = calculReste(distanceReste);
    Tableau<unsigned int> result = calculDepartReste(depart,distanceReste,reste);


    return result;

Tableau<double> Carte::calculReste (Tableau<double> *distanceReste[]) const {
    double max = std::numeric_limits<double>::max();
    Tableau<double> chemin;
    int position = 0;
    for(int i=0;i<3;i  ) {
        for (int j = 0; j < 3; j  ) {
            for (int k = 0; k < 3; k  ) {
                ...
                }
            }
        }
        *distanceReste[i] = max;
        max = std::numeric_limits<double>::max();

        position  = 3;
    }



    return chemin;
}

I kept it lighter to read it better.

I'd really appreciate it if you could help me out.

Thank you very much

Edit***

After seeing the answers that you guys gave me, i tried the following and it's still giving me an error:

Here's the function:

And he're the declaration of my functions in the header:

Still not working, I don't understand why?

CodePudding user response：

you don't have to pass the array with pointers because array in it default takes the address of the first element.so try the formal parameter without *.

CodePudding user response：

You can use function templates to pass the array by reference as shown below:

#include <iostream>

template<std::size_t N>
void func(int (&arr)[N])
{
    std::cout<<"size of array is: "<<N<<std::endl;
    std::cout<<"its elements are: "<<std::endl;
    for(int elem: arr)
    {
        std::cout<<elem<<std::endl;
    }
}


int main()
{
   
    int arrayToBePassed[4] = {1,45,23,54};
    func(arrayToBePassed);
    return 0;
}

So you have 2 options to solve your problem:

Solution 1

Make your calculReste function a member function template .

Solution 2

Pass the array be reference directly instead of pointer as shown below:

//note distanceReste is a reference to any array of fixed size 
Tableau<double> Carte::calculReste (Tableau<double> (&distanceReste)[4]) const {
    double max = std::numeric_limits<double>::max();
    Tableau<double> chemin;
    int position = 0;
    for(int i=0;i<3;i  ) {
        for (int j = 0; j < 3; j  ) {
            for (int k = 0; k < 3; k  ) {
                ...
                }
            }
        }
        *distanceReste[i] = max;
        max = std::numeric_limits<double>::max();

        position  = 3;
    }



    return chemin;
}

Also the declaration of calculReste inside the class will be changed to(if you choose solution 2):

Tableau<double> calculReste (Tableau<double> (&distanceReste)[4]) const;