title: Javascript: How can quotation mark be added to individual values in an array?
body: <p>I have a function that retrieve and display values of a csv file.</p>
  
  <p>function </p>
  
  <pre><code>var IDArr = [];
  var fileInput = document.getElementById("csv");
  
  readFile = function() {
    console.log("file uploaded")
    var reader = new FileReader();
    reader.onload = function() {
      // document.getElementById('out').innerHTML = reader.result;
  
      // I assigned the IDs retrieved from the CSV file to an array named keys
      IDArr.push(reader.result);
      // var keys = [reader.result];
      var promises = IDArr.map(function(key) {
        return firebase.database().ref("/Agents/").child(key).once("value");
      });
      // read the data from the database for each ID
      Promise.all(promises).then(function(snapshots) {
        snapshots.forEach(function(snapshot) {
          console.log(snapshot.key + ": " + snapshot.val());
        });
      });
    };
  
    // start reading the file. When it is done, calls the onload event defined above.
    reader.readAsBinaryString(fileInput.files[0]);
  };
  
  if (fileInput) {
    fileInput.addEventListener('change', readFile);
  }
  </code></pre>
  
  <p>the above function producess the image below </p>
  
  <p><a href="https://i.stack.imgur.com/5M7HM.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/5M7HM.png" alt="enter image description here"></a></p>
  
  <p>i need to put a quotation mark around each ID value and separate each with a comma. So for example I want to create a new array that looks like this "75799757","9744710", "79989647", "99029704" how can I implement this? </p>