Student Solution

scripts.js

@@ -1,32 +1,104 @@
 // FILL IN THE FUNCTIONS BELOW
 
 var sprintFunctions = {
-  largestEl: function(){  
-    // your code here
+  largestEl: function (arr) {
+    var largest = 0;
+    for (var i = 0; i < arr.length; i++) {
+      if (arr[i] > largest) {
+        largest = arr[i];
+      }
+    }
+    return largest;
   },
 
-  reversed: function(){  
-    // your code here
+  reversed: function(str) {  
+    var array = str.split('');
+    array.reverse();
+    return array.join('');
   },
 
-  loudSnakeCase: function(){  
-    // your code here
+  loudSnakeCase: function(s) {
+    // first remove punctuation
+    s = s.replace(/[.!]/g, "");
+    // replace whitespace groups > 1 with just 1 whitespace
+    s = s.replace(/\s{2,}/g, " ");
+    // split the string into an array of words
+    var words = s.split(" ");
+    // loop through every word
+    for (var i = 0; i < words.length; i++) {
+      // capitalize first letter of every word
+      words[i] = words[i].charAt(0).toUpperCase() + words[i].slice(1);
+    }
+    // join array of words together with underscores between them
+    return words.join("_");
+
   },
 
-  compareArrays: function(){ 
+  compareArrays: function(arrayA, arrayB) { 
     // your code here (replace the return)
-    return "Finish compareArrays first!" 
+    var arraysEqual = true;
+    if (arrayA.length !== arrayB.length) { arraysEqual = false; }
+
+    for (var i = 0; i < arrayA.length; i++) {
+      if (arrayA[i] !== arrayB[i]) {
+        arraysEqual = false;
+      }
+    } 
+
+    return arraysEqual;
+
   },
 
-  fizzBuzz: function(){  
-    // your code here
+  fizzBuzz: function(size) {
+    var result = [];
+    for (var i = 1; i <= size; i++) {
+      var divisibleBy3 = i % 3 === 0;
+      var divisibleBy5 = i % 5 === 0;
+      if (divisibleBy3 && divisibleBy5) {
+        result.push("FIZZBUZZ");
+      } else if (divisibleBy5) {
+        result.push("BUZZ");
+      } else if (divisibleBy3) {
+        result.push("FIZZ");
+      } else {
+        result.push(i);
+      }
+    }
+    return result;
   },
 
-  myMap: function(){  
-    // your code here
+  myMap: function(arr, func) {  
+    for (var i = 0; i < arr.length; i++) {
+      arr[i] = func(arr[i]);
+    }
+    return arr;
   },
 
-  primes: function(){  
-    // your code here
+  primes: function(n) {
+    // Eratosthenes algorithm to find all primes under n
+    var array = [], upperLimit = Math.sqrt(n), output = [];
+
+    // Make an array from 2 to (n - 1)
+    for (var i = 0; i < n; i++) {
+        array.push(true);
+    }
+
+    // Remove multiples of primes starting from 2, 3, 5,...
+    for (var i = 2; i <= upperLimit; i++) {
+        if (array[i]) {
+            for (var j = i * i; j < n; j += i) {
+                array[j] = false;
+            }
+        }
+    }
+
+    // All array[i] set to true are primes
+    for (var i = 2; i < n; i++) {
+        if(array[i]) {
+            output.push(i);
+        }
+    }
+
+    return output;
   },
 }