check if element indexes are inside 2d array (for moving by one in any direction)

Question

I have this two dimensional array of objects

private Cell[,] mapCells = new Cell[10, 10];

and I want to check if a key value pair with the coordinates x = m and y = n exists in my array.

I go for this

        bool cellExists = index.x >= 0 && // check left
              index.y >= 0 && // check bottom
              index.x < mapCells.GetLength(0) && // check right
              index.y < mapCells.GetLength(1); // check top

So with this bool I check if the cell would be on the map or outside.

Is there a more elegant way to check this?

EDIT:

When checking this I get a movement direction like

  Vector2 dir = new Vector2(/* this can be
     (0,1) // up
     (0,-1) // down
     (-1,0) // left
     (1,0) // right
  */);

So I know which direction is given.

When I move right I don't need to check the left side I think.

How do you define more elegant? It´s fairly opinion-based, isn´t it? — HimBromBeere
@HimBromBeere: I think he means shorter or faster. I see not much possibilities in either direction. — PMF
I'm voting to close this question as off-topic because it´s a review asking for improvement to working code and thus should go to codereview.stackexchange.com. — HimBromBeere

Rawitas Krungkaew Rawitas Krungkaew · Accepted Answer · 2018-01-23T08:12:45

Well, you could hide it behind the extension method to make it looks more elegant.

public static class Extensions
{
    public static bool IsExist(this Cell[,] mapCells, Cell index)
    {
        bool cellExists = index.x >= 0 &&
               index.y >= 0 &&
               index.x < mapCells.GetLength(0) &&
               index.y < mapCells.GetLength(1);

        return cellExists;
    }
}

Call it like this

mapCells.IsExist(index);

check if element indexes are inside 2d array (for moving by one in any direction)

3 Answers