Remove the last element from an array

Question

I want to remove the last entry in my array, and I want the array to show me that it has 1 less entry when I am using the ${#array[@]}. This is the current line

Answer 1

The following works fine for Mac/bash@3.x and Linux (ubuntu/bash@4.x)

unset arr[$[${#arr[@]}-1]] # non-sparse array only

in more details:

len=${#arr[@]}
idx=$[$len-1]    # <=> $(($len-1))
unset arr[$idx]