如何返回指向我的二维数组的指针？ C++

Question

The following is declared as global variable in a class:

int mazeLayout[MAZEHEIGHT][MAZEWIDTH]
    ={{1,1,1,1},
      {1,0,0,0}};

Then i have a public function that I want to return a pointer to the array called from another function in another class/header file:

int *getMazeLayout(){return *mazeLayout};

I get an error in here "expected ';' before '}' token"

Answer 1

There are many little corner cases here.

First a 2D int array is not an int ** - the latter should be an array of pointers pointing to the individual rows of the 2D array. They are used the same but are not same animal.

Here you could do:

int mazeLayout[MAZEHEIGHT][MAZEWIDTH]
    ={{1,1,1,1},
      {1,0,0,0}};
int *pMazeLayout[] = { mazeLayout[0], mazeLayout[1] };

int **getMazeLayout(){return pMazeLayout;}   // ; before }

But as you wanted to return a pointer to the 2D array, the exact way would be:

typedef int MAZE[MAZEHEIGHT][MAZEWIDTH];

MAZE *getMazeLayout() {
    return &mazeLayout;
}

You can then use:

MAZE *layout = getMazeLayout();
int val = (*layout)[1][2];

But it gives you an additional indirection level.

Alternatively you could just return a pointer to first row:

typedef int ROW[MAZEWIDTH];

ROW *getMazeLayout() {
    return mazeLayout;
}

You can then use:

ROW *layout = getMazeLayout();
int val = layout[1][2];