How to access individual variable inside of a 2d array Actionscript 3 - arrays

Question

Im trying to access an individual tile inside of my 2d array of tiles
Ive created my array like so:
private var map:Array = [[25,25]];
ive tried several ways including:
map[1][1] = 1;
all that does is give me this:
ReferenceError: Error #1056: Cannot create property 1 on Number.
ive also tried:
map[[1,1]] = 1;
nothing happends that I can tell
The only way that ive tried so far that gets me a result thats not an error is:
map[1,1] = 1;
The issue here is this selects the whole row.
Any help would be apreciated..thanks!

Answer 1

This is not correct way to create 2D array:
private var map:Array = [[25,25]];
This array contains one array which contains two elements. You can't address to the second element like this:
map[1][1] = 1;
because the second element (array) of map doesn't exist.
You can create 2D array this way:
var map:Array = [];
for (var i:int = 0; i < rows; i++)
{
map[i] = [];// this line adds new row to the 2D array
// To fill the array by zeros add next loop
for (var j:int = 0; j < cols; j++)
{
map[i][j] = 0;
}
}

Answer 2

To start, I think that to get the error mentioned in your question, your array should looks like this :
var map:Array = [
[25, 25], // map[0] = [25, 25] ( array of two elements )
35 // map[1] = 35 ( just a simple number )
];
So, if you write :
trace(typeof map[1]); // gives : number
You will get : number, and that's why you can not right : map[1][1] = value; and it's normal that you got the #1056 error.
Here, I don't know if you meant assign the value 1 to your 2nd 25 of map[0] or you want really add or edit map[1][1], in the 1st case, you can simply write :
map[0][1] = 1; // gives : map[0] = [25, 1]
In the 2nd case, you can do :
map[1] = [any_other_value, 1]; // gives : map[1] = [any_other_value, 1]
Last remark, forget that you got an error and suppose that your map array was just:
var map:Array = [
[25, 25]
];
Here, you can not also write map[1][1] = value;, why ? Let's use the same method :
trace(map[1]); // gives : undefined
So sure you can not add a property to an undefined, that's why when you write :
map[1][1] = value;
You will get an #1010 error : "undefined has no properties. ".
Of course here, we should firstly create map[1] :
map[1] = []; // or directly map[1] = [any_other_value, value]
And then :
map[1][1] = value;
Hope that can help.