Combine data from different cells in a table

I’m trying to read data stored in a csv file and present it in a table, using JavaScript. The csv data (comma delimited) is (I reduced it to be much smaller than the actual one):

Number, PDF1, PDF2, PDF3
0,,,
1,1.pdf,,
2,2a.pdf,2b.pdf,
3,3a.pdf,3b.pdf,3c.pdf

The correspondence between cells in the csv and online is 1 to 1, except 3 last columns (PDF1/2/3). I need them to appear online in the same cell (for each row) as links, separated by space. That is, instead of 3 columns PDF1/2/3 there will be just one, called PDF, containing links to pdfs 1, 2 and 3, if present. The desired output is:

| Number | PDF                                      |
| 0      |                                          |
| 1      | [link>1.pdf]                             |
| 2      | [link>2a.pdf] [link>2b.pdf]              |
| 3      | [link>3a.pdf] [link>3b.pdf] [link>3c.pdf]|

What I have so far:

html:

<span id="output"></span>

JS:

async function fetchCSV(url) {
    try {
        const response = await fetch(url);
        const data = await response.text();
        document.getElementById('output').innerText = data;
        processData(data);
    } catch (error) {
        console.error('Error fetching CSV:', error);
    }
}

//Link to csv file
fetchCSV('https://blabla/myfile.csv');

//read csv and save contents to variable "lines"
function processData(csv){
    var allTextLines = csv.split(/rn|n/);
    var lines = [];
    var keys = allTextLines.shift().split(','); //first line (headers) of csv
    while (allTextLines.length) {
        var arr = allTextLines.shift().split(',');
        var obj = {};
        for(var i = 0; i < keys.length; i++){
            obj[keys[i]] = arr[i];
    }
        lines.push(obj);
    }
    console.log(lines);
    drawOutput(lines);
}

//draw table function drawOutput(lines){
    //clear previous data
    document.getElementById("output").innerHTML = "";
    var table = document.createElement("table");

//first row (cols names) with "th"
var tableHeader = table.insertRow(-1);
Object.keys(lines[0]).forEach(function(key){
    if (key == "PDF1") {} //don't show "PDF1" column
    else if (key == "PDF2") {} //don't show "PDF2" column
    else {
        var el = document.createElement("TH");
        if (key == "PDF3") {el.innerHTML = "PDF";} //show "PDF3" column as "PDF"
        else {el.innerHTML = key;}
        tableHeader.appendChild(el);
    }
});

//the data (rest of the table)
for (var i = 0; i < lines.length-1; i++) {
    var row = table.insertRow(-1);
    Object.keys(lines[0]).forEach(function(key){
      if (key == "PDF1") {var pdflink1 = lines[i][key];}
      else if (key == "PDF2") {var pdflink2 = lines[i][key];}
      else if (key == "PDF3") {var pdflink3 = lines[i][key];
          var data = row.insertCell(-1);
          if (pdflink1 != []) {
              var a1 = document.createElement('a');
              a1.innerHTML = 'pdf1 ';
              a1.href = "dir/" + pdflink1;
              data.appendChild(a1);
          }
          if (pdflink2 != []) {
              var a2 = document.createElement('a');
              a2.innerHTML = 'pdf2 ';
              a2.href = "dir/" + pdflink2;
              data.appendChild(a2);
          }
          if (pdflink3 != []) {
              var a3 = document.createElement('a');
              a3.innerHTML = 'pdf3';
              a3.href = "dir/" + pdflink3;
              data.appendChild(a3);}
          }
      else {
    var data = row.insertCell(-1);
    data.appendChild(document.createTextNode(lines[i][key]));
  }});
}
document.getElementById("output").appendChild(table);
}

Everything seems to work OK, but I’m struggling to “keep” the pdf names in pdflink1 and pdflink2 to put them together with pdflink3 when key == “PDF3” is true. Out of three, only the latter is presented as desired in the output:

| Number | PDF                                         |
| 0      |                                             |
| 1      | [dir/undefined]                             |
| 2      | [dir/undefined] [dir/undefined]             |
| 3      | [dir/undefined] [dir/undefined] [dir/3c.pdf]|

I appreciate any assistance. Thank you.