Error while passing array as function parameter in bash - bash

Question

This is the code I am dealing with:
function execute {
task="$1"
servername="$2"
"$task" "${servername[#]}"
}
function someOtherThing {
val=$1
echo "$val"
}
function makeNecessaryDirectory {
arr=("$#")
echo "${arr[#]}"
}
dem=(1 2 3 4 5)
execute someOtherThing 1
execute makeNecessaryDirectory "${dem[#]}"
Output:
1
1
Expected output:
1
1 2 3 4 5
How to achieve this? I found no error logically.
Side question:
Is it safe to always receive 2nd parameter as an array inside execute so that it can deal with both of the dependent functions, or i should have an explicit check inside execute?

Answer 1

As explained in my comment
You are passing the array as individual args to execute and then only passing the first one the makeNecessaryDirectory, so $# is just the single argument passed which is 1.
I would do it this way, I have added comments to the parts i have changed.
It is only minor changes but should hopefully work for you.
#!/bin/bash
function execute {
task="$1"
servername="$2"
"$task" "$servername"
#No longer pass array here just pass servername as the name of array
}
function someOtherThing {
val=$1
echo "$val"
}
function makeNecessaryDirectory {
local arr=("${!1}")
#Indirect reference to the first arg passed to function which is now the
#name of the array
for i in "${arr[#]}";
do
echo "$i"
done
}
dem=(1 2 3 4 5)
execute someOtherThing 1
execute makeNecessaryDirectory 'dem[#]' #Pass the array name instead of it's contents