PHP - Get the multidimensional array index

I have a multidimensional array like this:

var squares = new Array();
            for(var i = 0; i <= 8; i++)
            {
                squares[i] = new Array();
                for(var j = (i * 20) + 1; j <= 20 * i + 20; j++)
                {
                    if (squares[i] == null)
                    {
                        squares[i] = ''+j;
                    }
                    else
                    {
                        squares[i].push('' + j);
                    }
                }
            }

I want to get the the index from the multidimensional array when I click on a square:

   angular.element('.click').click(function() {

            var squareId = angular.element(this).attr('id');                //Rutans id
            for(var k = 0; k <= 8; k++)
            {
                var squareIndex = squares[k].indexOf(squareId);
            }
            console.log(squareIndex);

But this only results in -1 by console.log. Anyone who can help me?

---

Using indexOf() you are only checking that the ID exists within that array. So if it occurs in the first array, it will continue to loop over them return -1 overwriting the previous value.

What you need to do is stop the loop when you find it and return k, the index of the array you are currently iterating through.

Here is a fiddle, hope this helps Fiddle

var squares = new Array();
    for(var i = 0; i <= 8; i++)
    {
        squares[i] = new Array();
        for(var j = (i * 20) + 1; j <= 20 * i + 20; j++)
        {
            if (squares[i] == null)
            {
                squares[i] = ''+j;
            }
            else
            {
                squares[i].push('' + j);
            }
        }
    }

console.log(squares);

$('a').on('click', function(){
var squareId = $(this).attr('id');
var squareIndex = 0,
    numberIndex = 0;

for(var k = 0; k < squares.length; k++)
{
    squareIndex = squares[k].indexOf(squareId);

    if (squareIndex > -1) {
        numberIndex = squareIndex;
        squareIndex = k;
        break
    }
}

    alert('NumberIndex: '+ numberIndex+' ParentSquareIndex: '+ squareIndex);
});