Adding elements of a bash array

I want to add the elements of a bash array together. I provide an example.

invalv=(1 1 1 1 1)
nval=5

Solution 1:

 nval=0
 invalv=(1 1 1 1 0)
 for i in "${invalv[@]}"; do (( nval+=i )); done
 printf '%s\n' "nval: $nval"