update snippets 47-62

snippets/head.md

@@ -6,5 +6,8 @@ Use `arr[0]` to return the first element of the passed array.
 
 ```js
 const head = arr => arr[0];
-// head([1,2,3]) -> 1
+```
+
+```js
+head([1,2,3]) -> 1
 ```