Sort and merge JSON keys with matching values

Question

My JSON looks like this:

json = [
  {
    type: \"big\"
    date: \"2012-12-08\"
    qty: 6
  }
  {
    type: \"small\"
    date: \"2012-12-08\"
    qty: 9
  }
          


        

Answer 1

One more to mix which I think this is the longest answer of them all :-)

    var sortedArray = [];

    function traverseArray(element, index, array) {
        
        var found = false;
        
        for (i = 0; i < sortedArray.length; i++) {
            if (sortedArray[i].type === element.type) {
                if (sortedArray[i].date.substring(0, 7) === element.date.substring(0, 7)) {
                    sortedArray[i].qty = (sortedArray[i].qty + element.qty);
                    console.log(element);
                    found = true;
                }
            }
        }
        
        if (!found)
            sortedArray.push(element);
    }
    
    
    
    var data = [{
        type: "big",
        date: "2012-12-08",
        qty: 6
    }, {
        type: "small",
        date: "2012-12-08",
        qty: 9
    }, {
        type: "big",
        date: "2012-12-15",
        qty: 4
    }, {
        type: "small",
        date: "2012-12-07",
        qty: 7
    }, {
        type: "small",
        date: "2012-11-07",
        qty: 3
    }];
    
    data.forEach(traverseArray);
    
    sortedArray.forEach(print);
    
    function print(element, index, array) {
        var line = "[ type: " + element.type + ", date: " + element.date + ", qty: " + element.qty + "]";
      $("#result").append(line  +  " 
");
    }