looping through arrays of arrays

For 2 dimenional Arrays:

for(var i = 0; i < parentArray.length; i++){
    for(var j = 0; j < parentArray[i].length; j++){

        console.log(parentArray[i][j]);
    }
}

For arrays with an unknown number of dimensions you have to use recursion:

function printArray(arr){
    for(var i = 0; i < arr.length; i++){
        if(arr[i] instanceof Array){
            printArray(arr[i]);
        }else{
            console.log(arr[i]);
        }
    }
}

if you just want to print all the members,how about this?

var items = parentArray.toString().split(",");
for(var i=0,j=items.length;i<j;i++)
    console.log(items[i]);

what you need to do is something like this

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]]
];

for(int i = 0; i < parentArray.length;i++){
   var value = parent[i];

   for(int j = 0; j < parent[i].length; j++){
      var innerValue = parent[i][j];
   }
}

So this will be like a nested loop, then there where innerValue and value is you can do some operations, hope it helps

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);