parse json to .csv in js

Question

I found this script (works well) except that I want to skip few columns (i just want to extract column 1,2,3,9) so I have this :

$(document).ready(function(){
    $('button').click(function(){
        var data = $('#txt').val();
        if(data == '') return;

        JSONToCSVConvertor(data, "Agenda", true);
    });
});

function JSONToCSVConvertor(JSONData, ReportTitle, ShowLabel) {
    //If JSONData is not an object then JSON.parse will parse the JSON string in an Object
    var arrData = typeof JSONData != 'object'
      ? JSON.parse(JSONData)
      : JSONData;

    var CSV = '';
    //Set Report title in first row or line
    CSV += ReportTitle + '\r\n\n';



    //This condition will generate the Label/Header
    if (ShowLabel) {
      var row = "";

      //This loop will extract the label from 1st index of on array
      for (var index = 0; i<arrData.length-1; index++) {
        if (index  == 4 || index == 5 || index == 6 || index == 7 || index == 8) {
          continue;
        }
        else{
          //Now convert each value to string and comma-seprated
          row += index + ';';

        row = row.slice(0, -1);
        //append Label row with line break
        CSV += row + '\r\n';
        }
    }
    //1st loop is to extract each row
    for (var i = 0; i < arrData.length-1; i++) {
      if (i  == 4 || i == 5 || i == 6 || i == 7 || i == 8) {
        continue;
      }
      else{
        var row = "";
      }
      //2nd loop will extract each column and convert it in string comma-seprated
      for (var j = 0; i<arrData.length-1; j++) {
          if (j  == 4 || j == 5 || j == 6 || j == 7 || j == 8) {
            continue;
          }
          else{
            row += '"' + arrData[i][j] + '";';
          }
        }
      }

      row.slice(0, row.length - 1);

      //add a line break after each row
      CSV += row + '\r\n';
    }



    if (CSV == '') {
      alert("Invalid data");
      return;
    }

    //Generate a file name
    var fileName = "Formapelec_";
    //this will remove the blank-spaces from the title and replace it with an underscore
    fileName += ReportTitle.replace(/ /g,"_");

    //Initialize file format you want csv or xls
    var uri = 'data:text/csv;charset=utf-8,' + escape(CSV);

    // Now the little tricky part.
    // you can use either>> window.open(uri);
    // but this will not work in some browsers
    // or you will not get the correct file extension

    //this trick will generate a temp <a /> tag
    var link = document.createElement("a");
    link.href = uri;

    //set the visibility hidden so it will not effect on your web-layout
    link.style = "visibility:hidden";
    link.download = fileName + ".csv";

    //this part will append the anchor tag and remove it after automatic click
    document.body.appendChild(link);
    link.click();
    document.body.removeChild(link);
}

It's supposed to generate a .csv with just column 1,2,3 & 9 but there's nothing in return. I tried different things with if() {continue} but I either have a return with all the columns or no return at all.

Answer 1

for (var i = 0; i < arrData.length-1; i++) {
      //2nd loop will extract each column and convert it in string comma-seprated
      for (var j = 0; j<arrData[i].length; j++) {
          if (j  == 4 || j == 5 || j == 6 || j == 7 || j == 8) {
            continue;
          }
          else{
            row += '"' + arrData[i][j] + '";';
          }
        }
      }

      row.slice(0, row.length - 1);

      //add a line break after each row
      CSV += row + '\r\n';
    }

you skipped rows, your second for was also wrong(incrementing j, but checking i, this would either run for ever or never run

Answer 2

//1st loop is to extract each row
for (var i = 0; i < arrData.length-1; i++) {
  if (i  == 4 || i == 5 || i == 6 || i == 7 || i == 8) {
    continue;
  }

You are skipping rows too, that if shouln't be there