diff --git a/aufgabe3/app.js b/aufgabe3/app.js
index c6f755c..e73c22b 100755
--- a/aufgabe3/app.js
+++ b/aufgabe3/app.js
@@ -1,11 +1,9 @@
 // DO NOT CHANGE!
 //init app with express, util, body-parser, csv2json
-var express = require('express');
-var app = express();
-var sys = require('util');
-var path = require('path');
-var bodyParser = require('body-parser');
-var Converter = require("csvtojson").Converter;
+const express = require('express');
+const app = express()
+const path = require('path');
+const bodyParser = require('body-parser');
 
 //register body-parser to handle json from res / req
 app.use(bodyParser.json());
@@ -20,63 +18,55 @@ app.use(express.static(path.join(__dirname, "public")));
 ****************************** csv2json *********************************
 **************************************************************************/
 
-const csv = require('csvtojson')
+const csv = require('csvtojson');
 
-var json;
+let csvdata;
 
 csv()
     .fromFile("world_data.csv")
     .then((jsonObj) => {
-        json = jsonObj;
-    })
+        csvdata = jsonObj;
+    });
+
 
 /**************************************************************************
 ********************** handle HTTP METHODS ***********************
 **************************************************************************/
 
+
 // ------------------------------ GET ------------------------------
 app.get("/items", function (req, res) {
-    console.log(json);
-    res.send(json);
+    res.send(csvdata);
 });
 
+
 app.get("/items/:id", function (req, res) {
-    var requested_id = parseInt(req.params.id);
-    var answer = ["Err", "No such id " + requested_id + " in database"];
+    const requested_id = parseInt(req.params.id);
+    let answer = "Err, No such id " + requested_id + " in database";
 
-    for (var i = 0; i < json.length; i++) {
-        if (json[i].id == requested_id) {
-            answer = [json[i]];
+    for (let i = 0; i < csvdata.length; i++) {
+        if (parseInt(csvdata[i].id) === requested_id) {
+            answer = csvdata[i];
         }
     }
 
     res.send(answer);
 });
 
+
 app.get("/items/:id1/:id2", function (req, res) {
-    var first_requested_id = parseInt(req.params.id1);
-    var second_requested_id = parseInt(req.params.id2);
-    var answer = ["Err", "Range not possible"];
+    const first_requested_id = parseInt(req.params.id1);
+    const second_requested_id = parseInt(req.params.id2);
+    let answer = "Err, Range not possible";
 
-    // check that first id is bigger than 0
-    // and the second one is the bigger one
-    if (first_requested_id >= 0 && second_requested_id > first_requested_id) {
-        var enable_push = false;
-
-        for (var i; i < json.length; i++) {
-            // enable push when the first id is found
-            if (parseInt(json[i].id) == first_requested_id) {
-                enable_push = true;
-            }
-
-            // push key when enabled
-            if (enable_push) {
-                answer.push(json[i]);
-            }
-
-            // break when second id is found
-            if (parseInt(json[i].id) == second_requested_id) {
-                break;
+    if (id_exists(first_requested_id) && id_exists(second_requested_id)
+        && first_requested_id < second_requested_id) {
+        answer = [];
+        for (let i = 0; i < csvdata.length; i++) {
+            if (parseInt(csvdata[i].id) >= first_requested_id) {
+                if (parseInt(csvdata[i].id) <= second_requested_id) {
+                    answer.push(csvdata[i]);
+                }
             }
         }
     }
@@ -84,66 +74,59 @@ app.get("/items/:id1/:id2", function (req, res) {
     res.send(answer);
 });
 
+
+
 app.get("/properties", function (req, res) {
-    var answer = [];
-
-    for (var key in json[0]) {
-        answer.push(key);
-    }
-
-    res.send(answer);
+    res.send(Object.keys(csvdata[0]));
 });
 
 app.get("/properties/:num", function (req, res) {
     let num = parseInt(req.params.num);
-    var answer = ["Err", "No such property available"];
+    let answer = "Err, No such property available";
 
-    var i = 0;
-
-    for (var key in json[0]) {
-        if (i == num) {
-            answer = [key];
-            break;
-        }
-
-        i++;
+    keys = Object.keys(csvdata[0]);
+    if (num >= 0 && num < keys.length) {
+        answer = keys[num];
     }
 
     res.send(answer);
-})
+});
+
+
 
 // ----------------------------- POST ------------------------------
 app.post("/items", function (req, res) {
-    var new_entry = req.body;
+    const new_entry = req.body;
 
     // set id
-    var last_id = parseInt(json[json.length - 1].id);
+    const last_id = parseInt(csvdata[csvdata.length - 1].id);
     new_entry["id"] = (last_id + 1).toString();
 
-    // add entry to json
-    json.push(new_entry);
+    // add entry to csvdata
+    csvdata.push(new_entry);
 
     res.send("Added country " + new_entry.name + " to list!");
 });
 
+
+
 // ---------------------------- DELETE -----------------------------
 app.delete("/items", function (req, res) {
-    var name = json[json.length - 1].name;
+    const name = csvdata[csvdata.length - 1].name;
 
-    json.splice(-1, 1);
+    csvdata.splice(-1, 1);
 
     res.send("Deleted last country " + name + "!");
 });
 
-app.delete("/items/id", function (req, res) {
-    var requested_id = parseInt(req.params.id);
-    var answer = ["Err", "No such id " + requested_id + "in database"];
-
-    for (var i = 0; i < json.length; i++) {
-        if (json[i].id == requested_id) {
-            json.splice(i, 1);
-            answer = ["Item " + requested_id + " deleted successfully."];
+app.delete("/items/:id", function (req, res) {
+    const requested_id = parseInt(req.params.id);
+    let answer = "Err, No such id " + requested_id + "in database";
 
+    for (let i = 0; i < csvdata.length; i++) {
+        if (parseInt(csvdata[i].id) === requested_id) {
+            csvdata.splice(i, 1);
+            answer = "Item " + requested_id + " deleted successfully.";
             break;
         }
     }
@@ -153,8 +136,18 @@ app.delete("/items/id", function (req, res) {
 
 // DO NOT CHANGE!
 // bind server to port
-var server = app.listen(3000, function () {
-    var host = server.address().address;
-    var port = server.address().port;
-    console.log('Example app listening at http://%s:%s', host, port);
-});
\ No newline at end of file
+const server = app.listen(3000, function () {
+    console.log('Example app listening at http://localhost:3000');
+});
+
+
+
+
+const id_exists = (id) => {
+    for (let i = 0; i < csvdata.length; i++) {
+        if (parseInt(csvdata[i].id) === first_requested_id) {
+            return true;
+        }
+    }
+    return false;
+};
\ No newline at end of file
diff --git a/aufgabe3/package.json b/aufgabe3/package.json
index 06ebee7..b0a7db3 100755
--- a/aufgabe3/package.json
+++ b/aufgabe3/package.json
@@ -4,7 +4,8 @@
   "description": "",
   "main": "app.js",
   "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "echo \"Error: no test specified\" && exit 1",
+    "start": "node app.js"
   },
   "author": "TEAM_00",
   "license": "ISC",