Sort by descending using underscore JS

Question

I have below code where I need to do sorting by underscore JS based on value of (y).

Please find my code below. I am trying to do ascending first and then reverse. Unfortunately, it is not doing the sorting at all for me and shows data without sorting.

        function getMessageNames(){
        var rowIter = 1;
        //document.getElementById("demo2").innerHTML += "from getMessageNames="+calltypes;
        for (var i in calltypes){
            keyId = calltypes[i].label;
            for (var index in keyMsgNames){
                if(keyMsgNames[index].Id == keyId){
                    var row = {"label":keyMsgNames[index].Name,"y":calltypes[i].y};
                    messageNames.push(row);
                    break;
                }
            }


// Result: 
//document.getElementById("demo2").innerHTML += "descending="+descending;
        }

            var ascending = _.sortBy(messageNames, ['y']); 
// Then get DESC 
var descending = ascending.reverse(); 
        for (var index in descending){
            addRow("CallTable", [ descending[index].label, descending[index].y], rowIter++);
        }
        createChart(descending,"Distribution on Key Messages",chartContainer);
    }

function createChart(data,title,container){
    var chart = new CanvasJS.Chart(container, {
                animationEnabled: true,
                title: {
                    text: title
                },
                data: [{
                    type: "pie",
                    startAngle: 240,
                    yValueFormatString: "",
                    indexLabel: "{label} '('{y}')'",
                    dataPoints: data
                }]
            });
            chart.render();
}

 function addRow(tblName, colData, rowNum){
    var table = document.getElementById(tblName);
    var tableRow = table.insertRow(rowNum);

    for (var index in colData){
        var cell = tableRow.insertCell(index);
        cell.innerHTML = colData[index];
    }
}

Answer 1

the sortBy expects an array of properties

Replace

var ascending = _.sortBy(messageNames, 'y'); 

with

var ascending = _.sortBy(messageNames, ['y']);