Javascript Complex Grouping

Question

I need help figuring out how I can loop through the Source Object to get the Output Strings. I currently have some nested for loops but I wind up missing one of the combinations or I get too much. The Number of Categories and Filters will vary

Source Object

var Source = {Cat1:{Filter1:'f1',Filter2:'f2'},
              Cat2:{Filter3:'f3',Filter4:'f4'},
              Cat3:{Filter5:'f5'}};

Output Strings

Filter1 Filter3 Filter5,
Filter1 Filter4 Filter5,
Filter2 Filter3 Filter5,
Filter2 Filter4 Filter5

Answer 1

Try this, this will return Array of arrays:

function cartesianProduct(paramArray) {

  function addTo(curr, args) {

    var i, copy, 
        rest = args.slice(1),
        last = !rest.length,
        result = [];

    for (i = 0; i < args[0].length; i++) {

      copy = curr.slice();
      copy.push(args[0][i]);

      if (last) {
        result.push(copy);

      } else {
        result = result.concat(addTo(copy, rest));
      }
    }

    return result;
  }


  return addTo([], Array.prototype.slice.call(arguments));
};

var Source = {Cat1:{Filter1:'f1',Filter2:'f2'},
              Cat2:{Filter3:'f3',Filter4:'f4'},
              Cat3:{Filter5:'f5'}};

// var cats = [];
var filters = [];

for(var c in Source) {
  filters.push([]);
  for(var f in Source[c])
    filters[filters.length - 1].push(f);
}


console.log(cartesianProduct.apply(this || window, filters));

HTH