CODEWITHSUNDEEP
c++multidimensional-array
BradStell
BradStell

Reputation: 500

C++ can't pass normal 2D array into method

I am creating a class that has a 2D array as a variable. I want users of the class to be able to use it with both a normal 2D array created on the stack ( int array[3][3] ) or be able to use it with a dynamic 2D array on the heap ( int *array[3] ). Then I will fill my class's 2D array with the incoming array no matter which type it is.

I have looked at this post: Passing a 2D array to a C++ function and a few others very similar. I followed the answers but I am still having issues. Here is what I am doing:

My class is called CurrentState, and I have two constructors with different signatures.

CurrentState.h

#ifndef A_STAR_CURRENTSTATE_H
#define A_STAR_CURRENTSTATE_H

class CurrentState
{
    private:
        int state[3][3];

    public:
        CurrentState(int** state);      // Dynamic array 
        CurrentState(int state[][3]);  // Normal array
        bool isFinishedState;
        bool checkFinishedState();
};

#endif

CurrentState.cpp

#include <iostream>
#include "currentState.h"

CurrentState::CurrentState(int** state) {

    // Fill class's state array with incoming array
    for (int i = 0; i < 3; i++)
    {
        for (int j = 0; j < 3; j++)
            this->state[i][j] = state[i][j];
    }
}

CurrentState::CurrentState(int state[][3])
{        
    // Fill class's state array with incoming array
    for (int i = 0; i < 3; i++)
    {
        for (int j = 0; j < 3; j++)
            this->state[i][j] = state[i][j];
    }
}

Then in my main() method I am doing this:

#include <iostream>
#include "currentState.h"

using namespace std;



int main()
{
    // Make dynamic array and pass into constructor
    int *array[3];
    for (int i = 0; i < 3; i++)
        array[i] = new int[3];

    CurrentState dynamic(array);

    // Make normal array and pass into constructor
    int a[3][3];

    CurrentState onStack(a); // <-- error says: "Class 'CurrentState' does not have a constructor 'CurrentState(int [3][3])'"


    return 0;
}

The first initiation of CurrentState in main() with the dynamic array works fine, however the second initiation of CurrentState with the normal array gives an error.

I am using CLion IDE by JetBrains, the method is underlined red and says: "Class 'CurrentState' does not have a constructor 'CurrentState(int[3][3])'"

Am I missing something? I'm pretty sure the class does have a constructor for a normal array ( int[3][3] ).

I have seen numerous other people in my searching doing the same thing, like here: http://www.cplusplus.com/forum/beginner/73432/ and in the link I posted at the beginning of my post.

Am I overlooking something? Any help will be greatly appreciated.

EDIT

I have removed the first parameter from the array and made it like so:

CurrentState(int state[][3]);

And I still have the same error

EDIt

From the command line it does compile, however it does not compile from within the IDE. I will just ignore the error while coding. False Alarm. Sorry people.

Upvotes: 2

Views: 114

Answers (1)

davepmiller
davepmiller

Reputation: 2708

Remove the first value from the bracket in your function definition.

Like so:

CurrentState::CurrentState(int state[][3])
{        
    ...
}

I'd also strongly recommend using std::array or std::vector as opposed to the c-style array. Your code for dynamic allocation already leaks memory unless you add the release loop below.

int *array[3];
for (int i = 0; i < 3; i++)
    array[i] = new int[3];

CurrentState dynamic(array);

//Kind of ugly cleanup here
for (int i = 0; i < 3; i++)
    delete[] array[i];

Upvotes: 2

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