Twig: How to get the first character in a string

Question

I am implementing an alphabetical search. We display a table of Names. I want to highlight only those alphabets, which have names that begin with the corresponding alphabet.

I am stumped with a simple problem.

How to read the first character in the string user.name within twig. I have tried several strategies, including the [0] operation but it throws an exception. Here is the code

{% for i in ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','0-9'] %}
       {% set has_user_starting_with_alphabet = false %}
       {% for user in pagination %}
              {% if user.name[0]|lower == i %}
                      {% set has_user_starting_with_alphabet = true %}
              {% endif %}
       {% endfor %}
       {% if has_user_starting_with_alphabet %}
              <li><a href="{{ path(app.request.get('_route'), { 'search_key' : i}) }}"><span>{{ i }}</span></a></li>
       {% endif %}
{% endfor %}

Is there some function like "starts_with" in twig?

Answer 1

Since twig 1.12.2 you can use first:

{% if user.name|first|lower == i %}

For older version you can use slice:

{% if user.name|slice(0, 1)|lower == i %}

Answer 2

Note: You may also use this notation:

{% if user.name[:1]|lower == i %}