diff --git a/packages/jspsych/src/modules/data/utils.ts b/packages/jspsych/src/modules/data/utils.ts
index 055d6f7f..fbaec318 100644
--- a/packages/jspsych/src/modules/data/utils.ts
+++ b/packages/jspsych/src/modules/data/utils.ts
@@ -23,35 +23,33 @@ export function saveTextToFile(textstr: string, filename: string) {
 // http://stackoverflow.com/users/317/joseph-sturtevant
 
 export function JSON2CSV(objArray) {
-  var array = typeof objArray != "object" ? JSON.parse(objArray) : objArray;
-  var line = "";
-  var result = "";
-  var columns = [];
+  const array = typeof objArray != "object" ? JSON.parse(objArray) : objArray;
+  let line = "";
+  let result = "";
+  const columns = [];
 
-  var i = 0;
-  for (var j = 0; j < array.length; j++) {
-    for (var key in array[j]) {
-      var keyString = key + "";
+  for (const row of array) {
+    for (const key in row) {
+      let keyString = key + "";
       keyString = '"' + keyString.replace(/"/g, '""') + '",';
       if (!columns.includes(key)) {
-        columns[i] = key;
+        columns.push(key);
         line += keyString;
-        i++;
       }
     }
   }
 
-  line = line.slice(0, -1);
+  line = line.slice(0, -1); // removes last comma
   result += line + "\r\n";
 
-  for (var i = 0; i < array.length; i++) {
-    var line = "";
-    for (var j = 0; j < columns.length; j++) {
-      var value = typeof array[i][columns[j]] === "undefined" ? "" : array[i][columns[j]];
+  for (const row of array) {
+    line = "";
+    for (const col of columns) {
+      let value = typeof row[col] === "undefined" ? "" : row[col];
       if (typeof value == "object") {
         value = JSON.stringify(value);
       }
-      var valueString = value + "";
+      const valueString = value + "";
       line += '"' + valueString.replace(/"/g, '""') + '",';
     }
 
@@ -66,10 +64,10 @@ export function JSON2CSV(objArray) {
 // http://stackoverflow.com/posts/3855394
 
 export function getQueryString() {
-  var a = window.location.search.substr(1).split("&");
-  var b = {};
-  for (var i = 0; i < a.length; ++i) {
-    var p = a[i].split("=", 2);
+  const a = window.location.search.substr(1).split("&");
+  const b = {};
+  for (let i = 0; i < a.length; ++i) {
+    const p = a[i].split("=", 2);
     if (p.length == 1) b[p[0]] = "";
     else b[p[0]] = decodeURIComponent(p[1].replace(/\+/g, " "));
   }