将带有变量的Vector的Vector传递给函数

Question

I was trying to create an array with variables for the size(ie array[x][y]), which won't work. I stumbled upon a post that suggested using a vector of a vector:

vector<vector<int> > grid(GetGridXComponent(), vector<int>(GetGridYComponent()));

The GetGridXComponent() and GetGridYComponent() retrieves private variables from a class.

The code works inside the function, but I need to be able to access the vector, "grid", outside of the class. To do this, I tried to create a public instance:

vector<vector<int> > grid(GetGridXComponent(), vector<int>(GetGridYComponent()));

But of course, GetGridXComponent() and GetGridYComponent() won't work because it thinks that I'm creating a function and wants me to declare a type for GetGridXComponent().

Is there a way of going about this? Am I making it harder than it needs to be? Thanks in advance.

Class Simulator
{
  private:
    int s_iGridXComponent;
    int s_iGridYComponent;
  public:
    Simulator();
    ~Simulator();
    int GetGridXComponent();
    int GetGridYComponent();
    void Function(vector<vector<int> >&);
  vector<vector<int> > pelletGrid(GetGridXComponent(), vector<int>(GetGridYComponent()));
}

void Simulator::Function(vector<vector<int> > &grid)
{
  code;
}

Answer 1

Assuming you are just trying to create a class member named pelletGrid that is a 2D vector it should be just something like:

class Simulator
{
    private:
        int s_iGridXComponent;
        int s_iGridYComponent;
        std::vector<std::vector<int>> pelletGrid;

    public:
        Simulator(const int x, const int y) : 
                s_iGridXComponent(x), 
                s_iGridYComponent(y), 
                pelletGrid(x, std::vector<int>(y)) 
        { }

        void CreateGrid (const int x, const int y)
        {
            s_iGridXComponent = x;
            s_iGridYComponent = y;

            pelletGrid = std::vector<std::vector<int>>(x, std::vector<int>(y));
        }

};

You can use either the constructor or the custom method in order to initialize the 2D vector depending on when you know the X/Y dimensions.