Value of var is not shown when concatenating $ and var --> $var

Question

I've got about a day of experience in bash as of now..

string () {
    for (( i=0; i<${#1}; i++ ))
    do
        echo "$"${1:$i:1}""
    done
}


string "hello"

This script returns "$h", "$e", "$l", "$l", "$o", but I actually want it to return the contents of variables h, e, l, l and o.

How do I do that?

Answer 1

You need to use indirect parameter expansion:

for ((i=0; i<${#1}; i++)); do
    t=${1:i:1}
    echo "${!t}"
done

${!t} takes the value of $t, and treats that as the name of the parameter to expand.