keys
ΒΆ
The keys
filter returns the keys of a sequence or a mapping. It is useful
when you want to iterate over the keys of a sequence or a mapping:
{% for key in ['a', 'b', 'c', 'd']|keys %}
{{ key }}
{% endfor %}
{# outputs: 0 1 2 3 #}
{% for key in {a: 'a_value', b: 'b_value'}|keys %}
{{ key }}
{% endfor %}
{# outputs: a b #}
Note
Internally, Twig uses the PHP array_keys function.