diff --git a/src/app.ts b/src/app.ts
index 42186e2..48cc280 100644
--- a/src/app.ts
+++ b/src/app.ts
@@ -26,15 +26,11 @@ let correct: string = "";
 //function to fetch all categories from the API
 async function getCategories() {
     try {
-        const endpoint = "api_category.php"
-
-        let categories = await getFunction(endpoint);
+        const categories = await getFunction<Categories>("api_category.php");
 
         if ('trivia_categories' in categories) {
-            categories as Categories;
-
             categories.trivia_categories.forEach((c: Category) => {
-                let category = document.createElement("option");
+                const category = document.createElement("option");
                 category.setAttribute('value', c.id);
                 category.textContent = c.name;
                 categoriesList?.appendChild(category);
@@ -51,21 +47,13 @@ getCategories();
 // function for creating the endpoint according to user input
 function createEndpoint() {
 
-    let amount = (document.getElementById("amount") as Input)?.value;
+    // What happens if the elements are not found?
+    const amount = (document.getElementById("amount") as Input)?.value;
     let category = categoriesList?.value;
     let difficulty = (document.getElementById("difficulty") as Options)?.value;
 
-    if (category === "any") {
-        category = "";
-    } else {
-        category = `&category=${category}`;
-    }
-
-    if (difficulty === "any") {
-        difficulty = "";
-    } else {
-        difficulty = `&difficulty=${difficulty}`;
-    }
+    category = category === "any" ? "" : `&category=${category}`;
+    difficulty = difficulty === "any" ? "" : `&difficulty=${difficulty}`;
 
     return `api.php?amount=${amount}${category}${difficulty}&type=multiple`;
 }
@@ -77,13 +65,12 @@ function generateQuiz() {
     quizFilterForm?.addEventListener("submit", async (e) => {
         e.preventDefault();
 
-        let endpoint = createEndpoint();
+        const endpoint = createEndpoint();
 
         // function for fetching the data
         try {
-            const questions = await getFunction(endpoint);
-            if ('results' in questions) {
-                questions as Data;
+            const questions = await getFunction<Data>(endpoint);
+            if (questions.results) {
                 allQuestions = questions.results;
 
                 // set item to local storage
@@ -151,18 +138,16 @@ function checkIfSelected(variable: Array<Question> | "", func1: (variable: Array
 
     if (checked) {
         //Test if something was checked
-        const alert = document.getElementById("alert");
-        if (alert) {
-            alert.remove();
-        }
+        document.getElementById("alert")?.remove();
 
         //save answers to localStorage
         if (checked?.parentNode?.textContent) {
             selectedAnswers.push(checked.parentNode.textContent.trim());
         }
 
-        encryptData("answers", selectedAnswers)
+        encryptData("answers", selectedAnswers);
 
+        // Bad name
         func1(variable);
 
     } else {
@@ -200,20 +185,21 @@ function checkResult() {
     let rightAns = 0;
 
     // get data from localStorage
+    // Use Generic Type <T>
     let questionsCorrectAnswers = decryptQuestions("questions-list");
     questionsCorrectAnswers.forEach((q) => {
-        let question = {
+        return {
             title: HTMLDecode(q.question),
             correctAnswer: HTMLDecode(q.correct_answer)
-        }
-        return question;
+        };
     });
-    let answered = decryptAnswers("answers");
+
+    const answered = decryptAnswers("answers");
 
     // compare data
     questionsCorrectAnswers as QCorrectAns[];
     questionsCorrectAnswers.forEach((a: QCorrectAns) => {
-        if (answered.includes(a.correct_answer)) {
+        if (answered.indexOf(a.correct_answer) > -1) {
             rightAns++;
         }
     });
diff --git a/src/utils/dataEncryption.ts b/src/utils/dataEncryption.ts
index df1b2a8..ddab2d9 100644
--- a/src/utils/dataEncryption.ts
+++ b/src/utils/dataEncryption.ts
@@ -8,10 +8,11 @@ export function encryptData(name: string, data: Question[] | string[]) {
     localStorage.setItem(name, encrypted);
 }
 
+//1 -> decryptQuestions and decryptAnswers can be the one function
 export function decryptQuestions(name: string): QCorrectAns[] {
     const encrypted = localStorage.getItem(name);
     if (typeof encrypted != 'string') {
-        throw Error('Data type is null.')
+        throw Error('Data type is null.');
     }
     const data = CryptoJS.AES.decrypt(encrypted, SECRET_KEY).toString(CryptoJS.enc.Utf8);
     const decrypted: QCorrectAns[] = JSON.parse(data);
@@ -21,7 +22,7 @@ export function decryptQuestions(name: string): QCorrectAns[] {
 export function decryptAnswers(name: string): string[] {
     const encrypted = localStorage.getItem(name);
     if (typeof encrypted != 'string') {
-        throw Error('Data type is null.')
+        throw Error('Data type is null.');
     }
     const data = CryptoJS.AES.decrypt(encrypted, SECRET_KEY).toString(CryptoJS.enc.Utf8);
     const decrypted: string[] = JSON.parse(data);
diff --git a/src/utils/universalModule.ts b/src/utils/universalModule.ts
index ef969cd..e6a09da 100644
--- a/src/utils/universalModule.ts
+++ b/src/utils/universalModule.ts
@@ -22,21 +22,22 @@ const createHeadersFn = (method: string, data: object | '') => {
     }
 
     return headers;
-}
+};
 
+// should have a catch, I dont like await
 // Function to perform a fetch request using the specified endpoint and headers
-const fetchFn = (endpoint: Endpoint, headers: Headers) => {
+const fetchFn = <T>(endpoint: Endpoint, headers: Headers) => {
     return fetch(url(endpoint), headers)
         .then(response => response.json())
-        .then((data: Data | Categories) => data);
-        // .catch((error: string) => console.error('Error fetching data:', error));
-}
+        .then((data: T) => data);
+    // .catch((error: string) => console.error('Error fetching data:', error));
+};
 
 // Function for making a GET request
-export const getFunction = (endpoint: Endpoint) => {
+export const getFunction = <T>(endpoint: Endpoint) => {
     const headers = createHeadersFn('GET', '');
-    return fetchFn(endpoint, headers);
-}
+    return fetchFn<T>(endpoint, headers);
+};
 
 // // Function for making a POST request
 // export const postFunction = (endpoint: Endpoint, body: object) => {
diff --git a/src/utils/worker.ts b/src/utils/worker.ts
index 44358c8..4d2c376 100644
--- a/src/utils/worker.ts
+++ b/src/utils/worker.ts
@@ -2,16 +2,14 @@ import { BlobWriter, TextReader, ZipWriter } from "@zip.js/zip.js";
 
 onmessage = async (e) => {
     const { feedback } = e.data;
-    if (typeof feedback != 'string') {
+    // Should be !==, not !=
+    if (typeof feedback != 'string')
         return;
-    } else {
-        feedback.replace(/<br\/>/g, '\n');
-
-        const zipWriter = new ZipWriter(new BlobWriter("application/zip"));
-        await zipWriter.add("QuizResult.txt", new TextReader(feedback));
-        const blob = await zipWriter.close();
-        postMessage(blob)
-    };
 
+    feedback.replace(/<br\/>/g, '\n');
 
+    const zipWriter = new ZipWriter(new BlobWriter("application/zip"));
+    await zipWriter.add("QuizResult.txt", new TextReader(feedback));
+    const blob = await zipWriter.close();
+    postMessage(blob);
 };
\ No newline at end of file