Add an example on how to iterate over a string

doc/tags/for.rst

@@ -139,3 +139,18 @@ the :doc:`slice <../filters/slice>` filter:
             <li>{{ user.username|e }}</li>
         {% endfor %}
     </ul>
+
+Iterating over a String
+-----------------------
+
+To iterate over the characters of a string, use the
+:doc:`split <../filters/split>` filter:
+
+.. code-block:: html+twig
+
+    <h1>Characters</h1>
+    <ul>
+        {% for char in "諺 / ことわざ"|split('') -%}
+            <li>{{ char }}</li>
+        {%- endfor %}
+    </ul>

tests/Fixtures/tags/for/for_on_strings.test

@@ -0,0 +1,13 @@
+--TEST--
+"for" tag can iterate over a string via the "split" filter
+--TEMPLATE--
+{% set jp = "諺 / ことわざ" %}
+
+{% for letter in jp|split('') -%}
+    -{{- letter }}
+    {{- loop.last ? '.' }}
+{%- endfor %}
+--DATA--
+return []
+--EXPECT--
+-諺- -/- -こ-と-わ-ざ.