Added the solutions to the arrays extra credit tasks

app/arraysExtraCredit.js

@@ -0,0 +1,54 @@
+exports = (typeof window === 'undefined') ? global : window;
+
+/*Pay special attention to what each function is supposed to return
+as well as what the .length property of each array should be*/
+exports.arraysExtraCreditAnswers = {
+
+  indexOf : function(arr, item) {
+    for (var i = 0; i < arr.length; i++) {
+      if (arr[i] === item) {
+        return i;
+      }
+    }
+    return -1;
+  },
+
+  push : function(arr,item) {
+    arr[arr.length] = item;
+    return arr.length;
+  },
+
+  pop : function(arr) {
+    var temp = arr[arr.length-1];
+    arr.length--;
+    return temp;
+  },
+
+  unshift : function(arr,item) {
+    for (var i = arr.length-1; i >= 0; i--) {
+      arr[i+1] = arr[i];
+    }
+    arr[0] = item;
+    return arr.length;
+  },
+
+  shift : function(arr) {
+    var temp = arr[0];
+    for (var i = 0; i < arr.length; i++) {
+      arr[i] = arr[i+1];
+    }
+    arr.length--;
+    return temp;
+  },
+
+  concat : function(arr1, arr2) {
+    var newArray = [];
+    for (var i = 0; i < arr1.length; i++) {
+      newArray.push(arr1[i]);
+    }
+    for (var i = 0; i < arr2.length; i++) {
+      newArray.push(arr2[i]);
+    }
+    return newArray;
+  }
+}