looping through arrays of arrays

I have an arrays of arrays (some thing like graph), How to iterate all arrays?

var parentArray = [
 [[1,2,3],[4,5,6],[7,8,9]],
 [[10,11,12],[13,14,15],[16,17,18]],
 [[19,20,21],[22,23,24],[26,27,28]]
];

Its just an example array, actual can contains any number of array and then arrays. How to print all those numbers? Its similar to html objects DOM

Answer

This recursive function should do the trick with any number of dimensions:

var printArray = function(arr) {
    if ( typeof(arr) == "object") {
        for (var i = 0; i < arr.length; i++) {
            printArray(arr[i]);
        }
    }
    else document.write(arr);
}

printArray(parentArray);