Update README.md

always define your variables at the top. defining them elsewhere is confusing because of hoisting. there is no block scope in javascript.

README.md

@@ -295,8 +295,9 @@
     }
 
     // good
+    var test;
     if (currentUser) {
-      var test = function test() {
+      test = function test() {
         console.log('Yup.');
       };
     }