diff --git a/functions-and-arrays.js b/functions-and-arrays.js
new file mode 100644
index 0000000..4bbbd59
--- /dev/null
+++ b/functions-and-arrays.js
@@ -0,0 +1,282 @@
+// Iteration #1: Find the maximum
+function maxOfTwoNumbers(num1, num2) {
+  return Math.max(num1, num2);
+}
+// Testing maximum function
+console.log(maxOfTwoNumbers(17,38))
+
+// Iteration #2: Find longest word
+const words = ['mystery', 'brother', 'aviator', 'crocodile', 'pearl', 'orchard', 'crackpot'];
+
+function findLongestWord(words) {
+  let longestWord = words[0];
+  for (let i =1; i < words.length; i++) {
+    if (words[i].length > longestWord.length){
+      longestWord = words[i];
+    }
+  }
+  return longestWord;
+}
+// Testing longest word function
+console.log(findLongestWord(words));
+
+// Iteration #3: Calculate the sum
+const numbers = [6, 12, 1, 18, 13, 16, 2, 1, 8, 10];
+
+function sumNumbers(numbers) {
+  let sum = 0;
+  for (let i = 0; i < numbers.length; i++){
+    sum = sum + numbers[i];
+  }
+  return sum;
+}
+// Testing sum function
+console.log(sumNumbers(numbers));
+
+// Iteration #3.1 Bonus:
+const mixedArr = [6, 12, 'miami', 1, true, 'barca', '200', 'lisboa', 8, 10];
+
+function sum(mixArr) {
+  let total = 0;
+  for (let i = 0; i<mixArr.length; i++){
+    const element = mixArr[i];
+
+    // Checking data type of each element and summing
+    if (typeof element === 'number'){
+      // total = total + element; //This notattion gives wrong answer
+      total += element; // Right answer
+    }
+    else if (typeof element === 'string'){
+      // total = total + element.length;
+      total += element.length
+    }
+    else if (typeof element === 'boolean'){
+      // total = total + element ? 1 : 0;
+      total += element ? 1: 0;
+    }
+    else{
+      throw new Error(`Unknown Data Type at index ${i}: ${element}`);
+    }
+  }
+  return total;
+}
+
+//Testing mix Array function
+console.log(sum(mixedArr));
+
+// Iteration #4: Calculate the average
+function average(numbers){
+  const sum = sumNumbers(numbers);
+  return sum / numbers.length;
+}
+
+// Test the Average
+console.log(average(numbers));
+
+// Level 1: Array of numbers
+const numbersAvg = [2, 6, 9, 10, 7, 4, 1, 9];
+
+function averageNumbers(numbers) {
+  if (numbers.length === 0) return null;
+
+  const sum = sumNumbers(numbers);
+  return sum / numbers.length;
+}
+
+// Test Average for numbers array
+console.log(averageNumbers(numbersAvg));
+
+// Level 2: Array of strings
+const wordsArr = ['seat', 'correspond', 'linen', 'motif', 'hole', 'smell', 'smart', 'chaos', 'fuel', 'palace'];
+
+function averageWordLength(words) {
+  if (words.length === 0) return null; // Check if arraay empty
+  
+  let totalLength = 0;
+  for (let i = 0; i < words.length; i++){
+    totalLength = totalLength + words[i].length;
+  }
+  return totalLength / words.length;
+}
+
+// Test average word length
+console.log(averageWordLength(wordsArr));
+
+// Bonus - Iteration #4.1
+function avg(arr) {
+  if (arr.length === 0) return null;
+
+  const sumTotal = sum(arr);
+  return sumTotal / arr.length;
+}
+
+// Test 4.1
+console.log(avg(mixedArr));
+
+// Iteration #5: Unique arrays
+const wordsUnique = [
+  'crab',
+  'poison',
+  'contagious',
+  'simple',
+  'bring',
+  'sharp',
+  'playground',
+  'poison',
+  'communion',
+  'simple',
+  'bring'
+];
+
+function uniquifyArray(words) {
+  let uniqueWords = [];
+
+  for (let i = 0; i < words.length; i++){
+    if (uniqueWords.indexOf(words[i]) === -1){
+      uniqueWords.push(words[i]);
+    }
+  }
+  return uniqueWords;
+}
+
+// Test Uniquify
+console.log(uniquifyArray(wordsUnique));
+
+// Iteration #6: Find elements
+const wordsFind = ['machine', 'subset', 'trouble', 'starting', 'matter', 'eating', 'truth', 'disobedience'];
+
+function doesWordExist(words, wordToSearch) {
+  for (let i = 0; i < words.length; i++){
+    if (words[i] === wordToSearch){
+      return true;
+    }
+  }
+  return false;
+}
+
+// Test word search
+console.log(doesWordExist(wordsFind, 'subset'));
+console.log(doesWordExist(wordsFind, 'Sekiro'));
+
+// Iteration #7: Count repetition
+const wordsCount = [
+  'machine',
+  'matter',
+  'subset',
+  'trouble',
+  'starting',
+  'matter',
+  'eating',
+  'matter',
+  'truth',
+  'disobedience',
+  'matter'
+];
+
+function howManyTimes(words, wordToCount) {
+  let count = 0;
+  for (let i = 0; i <words.length; i++){
+    if (words[i] === wordToCount){
+      count++;
+    }
+  }
+  return count;
+}
+
+// Test word count 
+console.log(howManyTimes(wordsCount, 'matter'));
+
+// Iteration #8: Bonus
+const matrix = [
+  [8, 2, 22, 97, 38, 15, 0, 40, 0, 75, 4, 5, 7, 78, 52, 12, 50, 77, 91, 8],
+  [49, 49, 99, 40, 17, 81, 18, 57, 60, 87, 17, 40, 98, 43, 69, 48, 4, 56, 62, 0],
+  [81, 49, 31, 73, 55, 79, 14, 29, 93, 71, 40, 67, 53, 88, 30, 3, 49, 13, 36, 65],
+  [52, 70, 95, 23, 4, 60, 11, 42, 69, 24, 68, 56, 1, 32, 56, 71, 37, 2, 36, 91],
+  [22, 31, 16, 71, 51, 67, 63, 89, 41, 92, 36, 54, 22, 40, 40, 28, 66, 33, 13, 80],
+  [24, 47, 32, 60, 99, 3, 45, 2, 44, 75, 33, 53, 78, 36, 84, 20, 35, 17, 12, 50],
+  [32, 98, 81, 28, 64, 23, 67, 10, 26, 38, 40, 67, 59, 54, 70, 66, 18, 38, 64, 70],
+  [67, 26, 20, 68, 2, 62, 12, 20, 95, 63, 94, 39, 63, 8, 40, 91, 66, 49, 94, 21],
+  [24, 55, 58, 5, 66, 73, 99, 26, 97, 17, 78, 78, 96, 83, 14, 88, 34, 89, 63, 72],
+  [21, 36, 23, 9, 75, 0, 76, 44, 20, 45, 35, 14, 0, 61, 33, 97, 34, 31, 33, 95],
+  [78, 17, 53, 28, 22, 75, 31, 67, 15, 94, 3, 80, 4, 62, 16, 14, 9, 53, 56, 92],
+  [16, 39, 5, 42, 96, 35, 31, 47, 55, 58, 88, 24, 0, 17, 54, 24, 36, 29, 85, 57],
+  [86, 56, 0, 48, 35, 71, 89, 7, 5, 44, 44, 37, 44, 60, 21, 58, 51, 54, 17, 58],
+  [19, 80, 81, 68, 5, 94, 47, 69, 28, 73, 92, 13, 86, 52, 17, 77, 4, 89, 55, 40],
+  [4, 52, 8, 83, 97, 35, 99, 16, 7, 97, 57, 32, 16, 26, 26, 79, 33, 27, 98, 66],
+  [88, 36, 68, 87, 57, 62, 20, 72, 3, 46, 33, 67, 46, 55, 12, 32, 63, 93, 53, 69],
+  [4, 42, 16, 73, 38, 25, 39, 11, 24, 94, 72, 18, 8, 46, 29, 32, 40, 62, 76, 36],
+  [20, 69, 36, 41, 72, 30, 23, 88, 34, 62, 99, 69, 82, 67, 59, 85, 74, 4, 36, 16],
+  [20, 73, 35, 29, 78, 31, 90, 1, 74, 31, 49, 71, 48, 86, 81, 16, 23, 57, 5, 54],
+  [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48]
+];
+
+function greatestProduct(matrix) {
+  let maxProduct = 0;
+
+  for (let i = 0; i<matrix.length; i++){
+    for (let j =0; j<matrix[i].length; j++){
+      if (j <=matrix[i].length - 4){
+        const horizontalProduct = matrix[i][j] * matrix[i][j+1] * matrix[i][j+2] * matrix[i][j+3];
+        maxProduct = Math.max(maxProduct, horizontalProduct); 
+      }
+
+      if (i <=matrix.length - 4){
+        const verticalProduct = matrix[i][j] * matrix[i+1][j] * matrix[i+2][j] * matrix[i+3][j];
+        maxProduct = Math.max(maxProduct, verticalProduct); 
+      }
+    }
+  }
+  return maxProduct;
+}
+
+// Test greatest Product matrix
+console.log(greatestProduct(matrix));
+
+// Diagonal product
+function greatestProductOfDiagonals(matrix) {
+  let maxProduct = 0; 
+
+  for (let i = 0; i < matrix.length; i++) {
+    for (let j = 0; j < matrix[i].length; j++) {
+      if (i <= matrix.length - 4 && j <= matrix[i].length - 4) {
+        const diagonalDownProduct = 
+          matrix[i][j] * 
+          matrix[i + 1][j + 1] * 
+          matrix[i + 2][j + 2] * 
+          matrix[i + 3][j + 3];
+        maxProduct = Math.max(maxProduct, diagonalDownProduct);
+      }
+
+      if (i >= 3 && j <= matrix[i].length - 4) {
+        const diagonalUpProduct = 
+          matrix[i][j] * 
+          matrix[i - 1][j + 1] * 
+          matrix[i - 2][j + 2] * 
+          matrix[i - 3][j + 3];
+        maxProduct = Math.max(maxProduct, diagonalUpProduct);
+      }
+    }
+  }
+  return maxProduct; // Return the greatest diagonal product found
+}
+
+// Test Diagonal produvet
+console.log(greatestProductOfDiagonals(matrix));
+
+// The following is required to make unit tests work.
+/* Environment setup. Do not modify the below code. */
+if (typeof module !== 'undefined') {
+  module.exports = {
+    maxOfTwoNumbers,
+    findLongestWord,
+    sumNumbers,
+    sum,
+    averageNumbers,
+    averageWordLength,
+    avg,
+    uniquifyArray,
+    doesWordExist,
+    howManyTimes,
+    greatestProduct
+  };
+}
diff --git a/src/functions-and-arrays.js b/src/functions-and-arrays.js
index 3a7dbec..4bbbd59 100644
--- a/src/functions-and-arrays.js
+++ b/src/functions-and-arrays.js
@@ -1,130 +1,282 @@
-// Iteration #1: Find the maximum
-function maxOfTwoNumbers() {}
-
-
-
-// Iteration #2: Find longest word
-const words = ['mystery', 'brother', 'aviator', 'crocodile', 'pearl', 'orchard', 'crackpot'];
-
-function findLongestWord() {}
-
-
-
-// Iteration #3: Calculate the sum
-const numbers = [6, 12, 1, 18, 13, 16, 2, 1, 8, 10];
-
-function sumNumbers() {}
-
-
-
-// Iteration #3.1 Bonus:
-function sum() {}
-
-
-
-// Iteration #4: Calculate the average
-// Level 1: Array of numbers
-const numbersAvg = [2, 6, 9, 10, 7, 4, 1, 9];
-
-function averageNumbers() {}
-
-
-// Level 2: Array of strings
-const wordsArr = ['seat', 'correspond', 'linen', 'motif', 'hole', 'smell', 'smart', 'chaos', 'fuel', 'palace'];
-
-function averageWordLength() { }
-
-// Bonus - Iteration #4.1
-function avg() {}
-
-// Iteration #5: Unique arrays
-const wordsUnique = [
-  'crab',
-  'poison',
-  'contagious',
-  'simple',
-  'bring',
-  'sharp',
-  'playground',
-  'poison',
-  'communion',
-  'simple',
-  'bring'
-];
-
-function uniquifyArray() {}
-
-
-
-// Iteration #6: Find elements
-const wordsFind = ['machine', 'subset', 'trouble', 'starting', 'matter', 'eating', 'truth', 'disobedience'];
-
-function doesWordExist() {}
-
-
-
-// Iteration #7: Count repetition
-const wordsCount = [
-  'machine',
-  'matter',
-  'subset',
-  'trouble',
-  'starting',
-  'matter',
-  'eating',
-  'matter',
-  'truth',
-  'disobedience',
-  'matter'
-];
-
-function howManyTimes() {}
-
-
-
-// Iteration #8: Bonus
-const matrix = [
-  [8, 2, 22, 97, 38, 15, 0, 40, 0, 75, 4, 5, 7, 78, 52, 12, 50, 77, 91, 8],
-  [49, 49, 99, 40, 17, 81, 18, 57, 60, 87, 17, 40, 98, 43, 69, 48, 4, 56, 62, 0],
-  [81, 49, 31, 73, 55, 79, 14, 29, 93, 71, 40, 67, 53, 88, 30, 3, 49, 13, 36, 65],
-  [52, 70, 95, 23, 4, 60, 11, 42, 69, 24, 68, 56, 1, 32, 56, 71, 37, 2, 36, 91],
-  [22, 31, 16, 71, 51, 67, 63, 89, 41, 92, 36, 54, 22, 40, 40, 28, 66, 33, 13, 80],
-  [24, 47, 32, 60, 99, 3, 45, 2, 44, 75, 33, 53, 78, 36, 84, 20, 35, 17, 12, 50],
-  [32, 98, 81, 28, 64, 23, 67, 10, 26, 38, 40, 67, 59, 54, 70, 66, 18, 38, 64, 70],
-  [67, 26, 20, 68, 2, 62, 12, 20, 95, 63, 94, 39, 63, 8, 40, 91, 66, 49, 94, 21],
-  [24, 55, 58, 5, 66, 73, 99, 26, 97, 17, 78, 78, 96, 83, 14, 88, 34, 89, 63, 72],
-  [21, 36, 23, 9, 75, 0, 76, 44, 20, 45, 35, 14, 0, 61, 33, 97, 34, 31, 33, 95],
-  [78, 17, 53, 28, 22, 75, 31, 67, 15, 94, 3, 80, 4, 62, 16, 14, 9, 53, 56, 92],
-  [16, 39, 5, 42, 96, 35, 31, 47, 55, 58, 88, 24, 0, 17, 54, 24, 36, 29, 85, 57],
-  [86, 56, 0, 48, 35, 71, 89, 7, 5, 44, 44, 37, 44, 60, 21, 58, 51, 54, 17, 58],
-  [19, 80, 81, 68, 5, 94, 47, 69, 28, 73, 92, 13, 86, 52, 17, 77, 4, 89, 55, 40],
-  [4, 52, 8, 83, 97, 35, 99, 16, 7, 97, 57, 32, 16, 26, 26, 79, 33, 27, 98, 66],
-  [88, 36, 68, 87, 57, 62, 20, 72, 3, 46, 33, 67, 46, 55, 12, 32, 63, 93, 53, 69],
-  [4, 42, 16, 73, 38, 25, 39, 11, 24, 94, 72, 18, 8, 46, 29, 32, 40, 62, 76, 36],
-  [20, 69, 36, 41, 72, 30, 23, 88, 34, 62, 99, 69, 82, 67, 59, 85, 74, 4, 36, 16],
-  [20, 73, 35, 29, 78, 31, 90, 1, 74, 31, 49, 71, 48, 86, 81, 16, 23, 57, 5, 54],
-  [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48]
-];
-
-function greatestProduct() {}
-
-
-
-
-// The following is required to make unit tests work.
-/* Environment setup. Do not modify the below code. */
-if (typeof module !== 'undefined') {
-  module.exports = {
-    maxOfTwoNumbers,
-    findLongestWord,
-    sumNumbers,
-    sum,
-    averageNumbers,
-    averageWordLength,
-    avg,
-    uniquifyArray,
-    doesWordExist,
-    howManyTimes,
-    greatestProduct
-  };
-}
+// Iteration #1: Find the maximum
+function maxOfTwoNumbers(num1, num2) {
+  return Math.max(num1, num2);
+}
+// Testing maximum function
+console.log(maxOfTwoNumbers(17,38))
+
+// Iteration #2: Find longest word
+const words = ['mystery', 'brother', 'aviator', 'crocodile', 'pearl', 'orchard', 'crackpot'];
+
+function findLongestWord(words) {
+  let longestWord = words[0];
+  for (let i =1; i < words.length; i++) {
+    if (words[i].length > longestWord.length){
+      longestWord = words[i];
+    }
+  }
+  return longestWord;
+}
+// Testing longest word function
+console.log(findLongestWord(words));
+
+// Iteration #3: Calculate the sum
+const numbers = [6, 12, 1, 18, 13, 16, 2, 1, 8, 10];
+
+function sumNumbers(numbers) {
+  let sum = 0;
+  for (let i = 0; i < numbers.length; i++){
+    sum = sum + numbers[i];
+  }
+  return sum;
+}
+// Testing sum function
+console.log(sumNumbers(numbers));
+
+// Iteration #3.1 Bonus:
+const mixedArr = [6, 12, 'miami', 1, true, 'barca', '200', 'lisboa', 8, 10];
+
+function sum(mixArr) {
+  let total = 0;
+  for (let i = 0; i<mixArr.length; i++){
+    const element = mixArr[i];
+
+    // Checking data type of each element and summing
+    if (typeof element === 'number'){
+      // total = total + element; //This notattion gives wrong answer
+      total += element; // Right answer
+    }
+    else if (typeof element === 'string'){
+      // total = total + element.length;
+      total += element.length
+    }
+    else if (typeof element === 'boolean'){
+      // total = total + element ? 1 : 0;
+      total += element ? 1: 0;
+    }
+    else{
+      throw new Error(`Unknown Data Type at index ${i}: ${element}`);
+    }
+  }
+  return total;
+}
+
+//Testing mix Array function
+console.log(sum(mixedArr));
+
+// Iteration #4: Calculate the average
+function average(numbers){
+  const sum = sumNumbers(numbers);
+  return sum / numbers.length;
+}
+
+// Test the Average
+console.log(average(numbers));
+
+// Level 1: Array of numbers
+const numbersAvg = [2, 6, 9, 10, 7, 4, 1, 9];
+
+function averageNumbers(numbers) {
+  if (numbers.length === 0) return null;
+
+  const sum = sumNumbers(numbers);
+  return sum / numbers.length;
+}
+
+// Test Average for numbers array
+console.log(averageNumbers(numbersAvg));
+
+// Level 2: Array of strings
+const wordsArr = ['seat', 'correspond', 'linen', 'motif', 'hole', 'smell', 'smart', 'chaos', 'fuel', 'palace'];
+
+function averageWordLength(words) {
+  if (words.length === 0) return null; // Check if arraay empty
+  
+  let totalLength = 0;
+  for (let i = 0; i < words.length; i++){
+    totalLength = totalLength + words[i].length;
+  }
+  return totalLength / words.length;
+}
+
+// Test average word length
+console.log(averageWordLength(wordsArr));
+
+// Bonus - Iteration #4.1
+function avg(arr) {
+  if (arr.length === 0) return null;
+
+  const sumTotal = sum(arr);
+  return sumTotal / arr.length;
+}
+
+// Test 4.1
+console.log(avg(mixedArr));
+
+// Iteration #5: Unique arrays
+const wordsUnique = [
+  'crab',
+  'poison',
+  'contagious',
+  'simple',
+  'bring',
+  'sharp',
+  'playground',
+  'poison',
+  'communion',
+  'simple',
+  'bring'
+];
+
+function uniquifyArray(words) {
+  let uniqueWords = [];
+
+  for (let i = 0; i < words.length; i++){
+    if (uniqueWords.indexOf(words[i]) === -1){
+      uniqueWords.push(words[i]);
+    }
+  }
+  return uniqueWords;
+}
+
+// Test Uniquify
+console.log(uniquifyArray(wordsUnique));
+
+// Iteration #6: Find elements
+const wordsFind = ['machine', 'subset', 'trouble', 'starting', 'matter', 'eating', 'truth', 'disobedience'];
+
+function doesWordExist(words, wordToSearch) {
+  for (let i = 0; i < words.length; i++){
+    if (words[i] === wordToSearch){
+      return true;
+    }
+  }
+  return false;
+}
+
+// Test word search
+console.log(doesWordExist(wordsFind, 'subset'));
+console.log(doesWordExist(wordsFind, 'Sekiro'));
+
+// Iteration #7: Count repetition
+const wordsCount = [
+  'machine',
+  'matter',
+  'subset',
+  'trouble',
+  'starting',
+  'matter',
+  'eating',
+  'matter',
+  'truth',
+  'disobedience',
+  'matter'
+];
+
+function howManyTimes(words, wordToCount) {
+  let count = 0;
+  for (let i = 0; i <words.length; i++){
+    if (words[i] === wordToCount){
+      count++;
+    }
+  }
+  return count;
+}
+
+// Test word count 
+console.log(howManyTimes(wordsCount, 'matter'));
+
+// Iteration #8: Bonus
+const matrix = [
+  [8, 2, 22, 97, 38, 15, 0, 40, 0, 75, 4, 5, 7, 78, 52, 12, 50, 77, 91, 8],
+  [49, 49, 99, 40, 17, 81, 18, 57, 60, 87, 17, 40, 98, 43, 69, 48, 4, 56, 62, 0],
+  [81, 49, 31, 73, 55, 79, 14, 29, 93, 71, 40, 67, 53, 88, 30, 3, 49, 13, 36, 65],
+  [52, 70, 95, 23, 4, 60, 11, 42, 69, 24, 68, 56, 1, 32, 56, 71, 37, 2, 36, 91],
+  [22, 31, 16, 71, 51, 67, 63, 89, 41, 92, 36, 54, 22, 40, 40, 28, 66, 33, 13, 80],
+  [24, 47, 32, 60, 99, 3, 45, 2, 44, 75, 33, 53, 78, 36, 84, 20, 35, 17, 12, 50],
+  [32, 98, 81, 28, 64, 23, 67, 10, 26, 38, 40, 67, 59, 54, 70, 66, 18, 38, 64, 70],
+  [67, 26, 20, 68, 2, 62, 12, 20, 95, 63, 94, 39, 63, 8, 40, 91, 66, 49, 94, 21],
+  [24, 55, 58, 5, 66, 73, 99, 26, 97, 17, 78, 78, 96, 83, 14, 88, 34, 89, 63, 72],
+  [21, 36, 23, 9, 75, 0, 76, 44, 20, 45, 35, 14, 0, 61, 33, 97, 34, 31, 33, 95],
+  [78, 17, 53, 28, 22, 75, 31, 67, 15, 94, 3, 80, 4, 62, 16, 14, 9, 53, 56, 92],
+  [16, 39, 5, 42, 96, 35, 31, 47, 55, 58, 88, 24, 0, 17, 54, 24, 36, 29, 85, 57],
+  [86, 56, 0, 48, 35, 71, 89, 7, 5, 44, 44, 37, 44, 60, 21, 58, 51, 54, 17, 58],
+  [19, 80, 81, 68, 5, 94, 47, 69, 28, 73, 92, 13, 86, 52, 17, 77, 4, 89, 55, 40],
+  [4, 52, 8, 83, 97, 35, 99, 16, 7, 97, 57, 32, 16, 26, 26, 79, 33, 27, 98, 66],
+  [88, 36, 68, 87, 57, 62, 20, 72, 3, 46, 33, 67, 46, 55, 12, 32, 63, 93, 53, 69],
+  [4, 42, 16, 73, 38, 25, 39, 11, 24, 94, 72, 18, 8, 46, 29, 32, 40, 62, 76, 36],
+  [20, 69, 36, 41, 72, 30, 23, 88, 34, 62, 99, 69, 82, 67, 59, 85, 74, 4, 36, 16],
+  [20, 73, 35, 29, 78, 31, 90, 1, 74, 31, 49, 71, 48, 86, 81, 16, 23, 57, 5, 54],
+  [1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 1, 89, 19, 67, 48]
+];
+
+function greatestProduct(matrix) {
+  let maxProduct = 0;
+
+  for (let i = 0; i<matrix.length; i++){
+    for (let j =0; j<matrix[i].length; j++){
+      if (j <=matrix[i].length - 4){
+        const horizontalProduct = matrix[i][j] * matrix[i][j+1] * matrix[i][j+2] * matrix[i][j+3];
+        maxProduct = Math.max(maxProduct, horizontalProduct); 
+      }
+
+      if (i <=matrix.length - 4){
+        const verticalProduct = matrix[i][j] * matrix[i+1][j] * matrix[i+2][j] * matrix[i+3][j];
+        maxProduct = Math.max(maxProduct, verticalProduct); 
+      }
+    }
+  }
+  return maxProduct;
+}
+
+// Test greatest Product matrix
+console.log(greatestProduct(matrix));
+
+// Diagonal product
+function greatestProductOfDiagonals(matrix) {
+  let maxProduct = 0; 
+
+  for (let i = 0; i < matrix.length; i++) {
+    for (let j = 0; j < matrix[i].length; j++) {
+      if (i <= matrix.length - 4 && j <= matrix[i].length - 4) {
+        const diagonalDownProduct = 
+          matrix[i][j] * 
+          matrix[i + 1][j + 1] * 
+          matrix[i + 2][j + 2] * 
+          matrix[i + 3][j + 3];
+        maxProduct = Math.max(maxProduct, diagonalDownProduct);
+      }
+
+      if (i >= 3 && j <= matrix[i].length - 4) {
+        const diagonalUpProduct = 
+          matrix[i][j] * 
+          matrix[i - 1][j + 1] * 
+          matrix[i - 2][j + 2] * 
+          matrix[i - 3][j + 3];
+        maxProduct = Math.max(maxProduct, diagonalUpProduct);
+      }
+    }
+  }
+  return maxProduct; // Return the greatest diagonal product found
+}
+
+// Test Diagonal produvet
+console.log(greatestProductOfDiagonals(matrix));
+
+// The following is required to make unit tests work.
+/* Environment setup. Do not modify the below code. */
+if (typeof module !== 'undefined') {
+  module.exports = {
+    maxOfTwoNumbers,
+    findLongestWord,
+    sumNumbers,
+    sum,
+    averageNumbers,
+    averageWordLength,
+    avg,
+    uniquifyArray,
+    doesWordExist,
+    howManyTimes,
+    greatestProduct
+  };
+}