unusual bash array command

Question

Found this snippet of code which uses an array in Bash.

unset var1[@]

for i in {0..23}
do
    var1[10#$i]="some data"
done

When setting the element with data, what's that 10# in front of the element number for?

I know that for showing the total number of elements you can use echo ${#var1[@]} but I don't think the hash in setting the element has something to do with total size.

Answer 1

In arithmetic expressions, you can use # to specify base :

$ echo $((2#1110))
14

Using 10#$i would prevent i=08 from failing with value too great for base and interpret it as 8 . For 0 .. 23, it's equivalent to just i .