How to use shell variables in su command string?

Question

In Shell script i am trying to pass an array to a Sudo SU command as shown below

VAR=(1,2,3)
sudo su $USER -c "for p in ${VAR[@]} ; do echo $p ; done;"

Issue is $p value is not getting printed. I have tried all the below possible way but not able to print $p value

sudo su $USER -c "for p in "${VAR[@]}" ; do echo "$p" ; done;"
sudo su $USER -c 'for p in ${VAR[@]} ; do echo $p ; done;'

Sample Output of the command

+ sudo su USER -c 'for p in 1 2 3 4 5 ; do echo  ; done;'
+ echo "Script Ended"

Answer 1

You could use sh as an argument to sudo su, to pass the variable, then, inside the -c call, you can access the var as you would do in a regular function call ($@ $1 ...);

sudo su $USER -c 'for p in "${@}"; do echo ${p}; done;' sh "${arr[@]}"

so@deb:~$ arr=(1 2 3)
so@deb:~$ sudo su $USER -c 'for p in "${@}"; do echo ${p}; done;' sh "${arr[@]}"
1
2
3
so@deb:~$