Inline and multiline comments in Craft?

Question

How do comments work in Craft? I mean inline and multiline comments, like:

HTML: <!--xxx--> m
  JS:   /*xxx*/  m   //xxx i
 PHP:   /*xxx*/  m   //xxx i   #xxx i

Answer 1

There's only one comment syntax for Craft / Twig:

{# ... #}

Anything in between won't be parsed by Twig, so you can comment out multiple lines of Twig and HTML like so:

{# 
    {% set var = value %}
    {% for item in seq %}
        <p>{{ item }}</p>
    {% endfor %}
#}

As with many other languages you can't nest comments! So if you want to comment out some lines of code that already have comments, you can't do that like so:

{# 
    {#
     # Lots of comments going on here
     #}
    {% set var = value %}

    {# I warned you #}
    {% for item in seq %}
        <p>{{ item }}</p>
    {% endfor %}
#}

The best workaround I found is to use HTML comments in combination with Twigs verbatim tags (disables Twig parsing). I added a snippet to my editor for this and use it regularly since:

{% verbatim %}
<!--
    {#
     # Lots of comments going on here
     #}
    {% set var = value %}

    {# I warned you #}
    {% for item in seq %}
    {% endfor %}
-->
{% endverbatim %}