Add concatenation to toString()

A number of different routes could be taken to print out the list.  This change will concatenate the string to print each element on a separate line.

Author: jaygood

chapter05/01-Linked-List.js

@@ -138,7 +138,7 @@ function LinkedList() {
             string = '';
 
         while (current) {
-            string = current.element;
+            string += current.element + (current.next ? '\n' : '');
             current = current.next;
         }
         return string;
@@ -148,4 +148,4 @@ function LinkedList() {
     this.print = function(){
         console.log(this.toString());
     };
-}
+}