How to simplify the comparison in the bash?

how to make several comparisons in the bash by placing the condition and comparison points next to instead of the long queue ?

that something like this

before :

if [[ $var == "aaa" || $var == "bbb" || $var == "ccc" || $var == "ddd" ]];
then
 echo "good";
fi

after (what I want):

if [[ $var==["aaa","bbb","ccc","ddd"] ]];
then
 echo "good";
fi

Answer

Try this using bash regex with the keywork =~:

if [[ $var =~ ^(aaa|bbb|ccc|ddd)$ ]];
then
 echo "good";
fi

Edit :

As seen in comments, for real you need to compare int, not strings, so :

((var%3 == 0)) && echo "ok"

Using bash arithmetic