Convert a nested array to plain Arrays

Question

I have an array like below

var arr = [["a", "b"],[1],[5,6]];

I would like to convert it to plain JSON like below

arr = [
     ["a","a","b","b"]
     [1,1,1,1]
     [5,6,5,6]
]

The logic is

Under each item of first array element all the elements are sub elements, under next each array items of [1], [5,6] are sub elements

a->1->[5,6]
b->1->[5,6]

if var arr = [["a", "b"],[1,2],[5,6]]; then

a->[1]->[5,6]
a->[2]->[5,6]

like the same with element b also. I am struck, as I don't know how to proceed

Answer 1

Like this?:

var arr = [["a", "b"],[1],[5,6]];

var convert2PlainArray = function(array){
    var totalLength = 1,
        plainArray = [];
    for(var i=0;i<array.length; i++){
        totalLength*=array[i].length;
    }
    for(var i=0;i<array.length; i++){
        var currentElementLength = totalLength/array[i].length,
            tempArray = [];
        for(var e=0;e<array[i].length; e++){
            for(var l=0;l<currentElementLength; l++)tempArray.push(array[i][e]);
        }
        plainArray.push(tempArray);
    }
    return plainArray;
}

alert(JSON.stringify(convert2PlainArray(arr)));

Test it on fiddle: http://jsfiddle.net/GMJzW/