Setting element of array from Twig

Question

How can I set member of an already existing array from Twig?

I tried doing it next way:

{% set arr[\'element\'] = \'value\' %}

but

Answer 1

I have tried @LivaX 's answer but it does not work , merging an array where keys are numeric wont work ( https://github.com/twigphp/Twig/issues/789 ).

That will work only when keys are strings

What I did is recreate another table ( temp) from the initial table (t) and make the keys a string , for example :

{% for key , value in t%}
{% set temp= temp|merge({(key~'_'):value}) %}
{% endfor %}

t keys : 0 , 1 , 2 ..

temp keys : 0_, 1_ , 2_ ....