Can I offer other way (via associative array) to do your task? It seems more clever and acceptable:

declare -A array
for i in ${alphabet[@]}; do
  array[$i]=0
done

So you can iterate through it by for i in ${!array[@]} or same for i in ${alphabet[@]}

Can I offer other way (via associative array) to do your task? It seems more clever and acceptable:

declare -A array
for i in ${alphabet[@]}; do
  array[$i]=0
  # or array[${i}0]=0 if you need 
done

So you can iterate through it by for i in ${!array[@]} or same wayfor i in ${alphabet[@]}