Cont'd Day1, completed level3 function exercises, will now merge branch to master, continuing with HOF,Desctrucing and Spreading

solutions/day-01/functions/level3.js

@@ -3,16 +3,46 @@
 
 
 // Call your function shuffleArray, it takes an array as a parameter and it returns a shuffled array
-
+let foodArray = ['Chicken', 'Rice', 'Butter', 'Salad'];
+let shuffleArray = (...array) => {
+    for (let i = array.length - 1; i > 0; i--) {
+        const j = Math.floor(Math.random() * (i + 1));
+        const temp = array[i];
+        array[i] = array[j];
+        array[j] = temp;
+    }
+    return array;
+}
+console.log(shuffleArray(...foodArray));
 
 
 // Call your function factorial, it takes a whole number as a parameter and it return a factorial of the number
-
+function factorial(num){
+    let total =  1;
+    for(let i = 1; i <= num; i++){
+        total = total * i;
+    }
+    return total;
+}
+console.log(factorial(5));
 
 
 // Call your function isEmpty, it takes a parameter and it checks if it is empty or not
-
-
+let numbers = [1,2,3,4];
+let isEmpty = (...array) => {  
+    return (array.length == 0) ?  'Array is empty': 'Array is not empty'
+}
+console.log(isEmpty(...numbers))
 
 // Write a function called average, it takes an array parameter and returns the average of the items. 
-// Check if all the array items are number types. If not give return reasonable feedback.
+// Check if all the array items are number types. If not give return reasonable feedback.
+let nums = [1,2,3,4,5,6];
+let average = (...array) => {
+    let message = '';
+    let avg = 0;
+    array.forEach(element => {
+        return (typeof element == 'number') ? avg = (avg + element) : message = 'Error, an element of the array is not a number';
+    });
+    return (message.length > 0) ? message : avg / array.length;
+}
+console.log(average(...nums))