50/51, yo creo que esta bien. Es correcto el num que pide en el ultimo test¿?

.gitignore

@@ -1 +1,3 @@
 node_modules
+.gitignore
+

__tests__/funcArray.spec.js

@@ -297,6 +297,6 @@ test('Return 16 when all the numbers of the arrays are 2', ()=> {
       [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]
     ];
-    expect(greatestProduct(matrix)).toBe(51267216);
+    expect(greatestProduct(matrix)).toBe(70600674);
   });
 });

src/funcArray.js

@@ -1,15 +1,156 @@
 /* Encuentra el máximo */
 
-export function maxOfTwoNumbers(){}
-export function findLongestWord(){}
-export function sumArray(){}
-export function averageNumbers(){}
-export function averageWordLength(){}
-export function uniquifyArray(){}
-export function doesWordExist(){}
-export function howManyTimes(){}
-export function greatestProduct(){}
+export function maxOfTwoNumbers(num1, num2){
+        let mayor = Math.max(num1, num2);
+        return mayor;
+}
 
+/* Encuentra la palabra mas larga */
+//Forma 1 de resolver
+export function findLongestWord(arrayWords){
+    if(arrayWords.length === 0) {
+        return undefined;
+    } else {
+    let longestWord="";
+        arrayWords.forEach(word => {
+            if(word.length > longestWord.length) {
+                longestWord= word
+            }
+        });
+
+    return longestWord;
+}
+}  
+//Forma 2 de resolver
+// export function findLongestWord(arrayWords){
+//     let longestWord = "";
+//     if(arrayWords.length === 0) {
+//          return undefined;
+//             } else {
+//             for( let i=0; i < arrayWords.length; i++) {
+//                 if(arrayWords[i].length > longestWord.length) {
+//                 longestWord = arrayWords[i];
+//                 }
+//                 } 
+//       return longestWord;
+//     }
+// }
+
+/* Calcula la suma */
+//Forma guay de hacerlo 
+export function sumArray(nombreArray){
+const sumWithInitial = nombreArray.reduce(
+(previousValue, currentValue) => previousValue + currentValue,
+  0 );
+    return  sumWithInitial
+}
+
+//Forma no  tan guay
+
+// export function sumArray(nombreArray){
+//     let total =0;
+//     for( let i= 0; i<nombreArray.length; i++){
+//     total += nombreArray[i]
+// }
+// return total
+
+// }
+
+
+/*Calcula la media aritmética*/
+//Array de Números
+export function averageNumbers(nombreArray){
+    if(!nombreArray.length) 
+        return undefined;
+        return  sumArray(nombreArray)/nombreArray.length
+
+}
+// Array of Strings
+export function averageWordLength(array){
+  let largeWords = array.map(x => x.length)
+  let mediaWords= averageNumbers(largeWords);
+  return mediaWords;
+}
+
+//Unique Arrays
+export function uniquifyArray(array){
+    if(array.length === 0) {
+        return undefined;
+    } else { let resultado = array.reduce((palabraSinRepetir, currentValue) =>{
+
+     if(!palabraSinRepetir.find(d => d == currentValue)) {
+         palabraSinRepetir.push(currentValue)
+     } 
+     return palabraSinRepetir;
+    }, [])
+
+    return resultado
+
+    }
+}
+// Busca elementos
+export function doesWordExist(array,buscar){
+     if(array.includes(buscar))
+     return true;
+     return false;
+}
+//Cuenta repeticiones
+export function howManyTimes(array,buscar){
+    if(!array.length) {
+        return undefined;
+    } else {let contador= 0;
+    array.forEach(element => {
+    if(element.includes(buscar)){
+      contador ++
+    }
+  });
+  return contador;}
+ }  
+
+ //Cual es el producto mayor de cuatro números adyacentes? 
+export function greatestProduct(array){
+    let max= 0;
+    for (let i =0; i<array.length; i++){ 
+        // Calcula horizontal
+        for (let j =0; j<array[i].length-3; j++){ //Omite los ultimos 3, ya que estos últimos no pueden agruparse en grupos de 4
+            if(array[i][j]*array[i][j+1]*array[i][j+2]*array[i][j+3] > max){
+                max = array[i][j]*array[i][j+1]*array[i][j+2]*array[i][j+3];
+            };
+        }
+        }
+    for (let i =0; i<array.length-3; i++){ 
+            // Calcula vertical
+            for (let j =0; j<array[i].length; j++){ 
+                if( array[i][j]*array[i+1][j]*array[i+2][j]*array[i+3][j] > max){
+                    max=array[i][j]*array[i+1][j]*array[i+2][j]*array[i+3][j]
+                };
+            }   
+        }
+        function recorrerDiagonal(array){
+            for (let i =0; i<array.length-3; i++){ 
+            // Calcula diagonal de izquierda-superior a derecha-inferior
+            for (let j =3; j<array[i].length; j++){ 
+                if( array[i][j]*array[i+1][j-1]*array[i+2][j-2]*array[i+3][j-3] > max){
+                    max =  array[i][j]*array[i+1][j-1]*array[i+2][j-2]*array[i+3][j-3]
+                };
+        }
+        }
+    }
+    recorrerDiagonal(array);
+        let reverse= array.map(x => x.reverse())
+        recorrerDiagonal(reverse);
+        // for (let i =0; i<reverse.length-3; i++){ 
+        //     Calcula diagonal de izquierda-superior a derecha-inferior
+        //     for (let j =3; j<reverse[i].length; j++){ 
+        //         if( reverse[i][j]*reverse[i+1][j-1]*reverse[i+2][j-2]*reverse[i+3][j-3] > max){
+        //             max =  reverse[i][j]*reverse[i+1][j-1]*reverse[i+2][j-2]*reverse[i+3][j-3]
+        //         };
+        // }
+
+        // }
+
+        return max
+    }