HTML

twig last item

{% for elem in arrMenu %}
    {% if loop.first %}
    <div class="topmenu-button first">        
    {% elseif loop.last %}
    <div class="topmenu-button last">        
    {% else %}
    <div class="topmenu-button">        
    {% endif %}
        <a href="{{ elem.url }}">{{ elem.name }}</a>
    </div>
{% endfor %}

twig last

{{ [1, 2, 3, 4]|last }}
{# outputs 4 #}

{{ { a: 1, b: 2, c: 3, d: 4 }|last }}
{# outputs 4 #}

{{ '1234'|last }}
{# outputs 4 #}