Multidimensional associative arrays in Bash

Question

I\'m trying to create a multidimensional associative array but need some help. I have reviewed the page suggested in this SO answer but it confused me even more. So far here

Answer 1

I understand what you need. I also wanted the same for weeks. I was confused whether to use Python or Bash. Finally, exploring something else I found this Bash: How to assign an associative array to another variable name (e.g. rename the variable)?

Here, I got to know how to assign some string and use it later as command. Then with my creativity I found solution to your problem as below:-

---

#!/bin/bash

declare -A PERSONS
declare -A PERSON

PERSON["FNAME"]='John'
PERSON["LNAME"]='Andrew'
string=$(declare -p PERSON)
#printf "${string}\n"
PERSONS["1"]=${string}
#echo ${PERSONS["1"]}

PERSON["FNAME"]='Elen'
PERSON["LNAME"]='Murray'
string=$(declare -p PERSON)
#printf "${string}\n"
PERSONS["2"]=${string}
#echo ${PERSONS["2"]}

for KEY in "${!PERSONS[@]}"; do
   printf "$KEY - ${PERSONS["$KEY"]}\n"
   eval "${PERSONS["$KEY"]}"
   printf "${PERSONS["$KEY"]}\n"
   for KEY in "${!PERSON[@]}"; do
      printf "INSIDE $KEY - ${PERSON["$KEY"]}\n"
   done
done

---

OUTPUT:-

1 - declare -A PERSON='([FNAME]="John" [LNAME]="Andrew" )'

declare -A PERSON='([FNAME]="John" [LNAME]="Andrew" )'

INSIDE FNAME - John

INSIDE LNAME - Andrew

2 - declare -A PERSON='([FNAME]="Elen" [LNAME]="Murray" )'

declare -A PERSON='([FNAME]="Elen" [LNAME]="Murray" )'

INSIDE FNAME - Elen

INSIDE LNAME - Murray

---

The problem actually with multi dimensional arrays in bash and specifically in your approach is that you are assigning PERSON array values to the array element PERSONS[1] which is converted to a list and not an assoc array when you assigned it. And so it no longer will take it as 2 elements of an array as you are not keeping any info about the array data structure in your value. So, I found this hack to be sufficient with only 1 limitation that you will have to do this each time you want to do store/retrieve values. But it shall solve your purpose.