Bash has associative arrays, but just POSIX shells like ash do not have associative arrays. And, POSIX shell can only shift and unshift on the $@ array; so it

Bash has associative arrays, but just POSIX shells like ash do not have associative arrays. And, POSIX shell can only shift and unshift on the $@ array; so it would be necessary to implement hashmaps or associative arrays with shell string methods and/or eval.