Merge pull request basarat#394 from jamestharpe/master

Adds missing else in err falsy check

Author: basarat

docs/javascript/null-undefined.md

@@ -73,8 +73,9 @@ Node style callback functions (e.g. `(err,somethingElse)=>{ /* something */ }`)
 fs.readFile('someFile', 'utf8', (err,data) => {
   if (err) {
     // do something
+  } else {
+    // no error
   }
-  // no error
 });
 ```
 When creating your own APIs it's *okay* to use `null` in this case for consistency. In all sincerity for your own APIs you should look at promises, in that case you actually don't need to bother with absent error values (you handle them with `.then` vs. `.catch`).