Bash arrays and negative subscripts, yes or no?

Question

The GNU bash manual tells me

An indexed array is created automatically if any variable is assigned to using the syntax

name[subscript]=v         


        

Answer 1

Old bashes (like the default one on Macs these days) don't support negative subscripts. Apart from the "substring expansion" used in the accepted answer, a possible workaround is to count the desired index from the array start within the brackets:

$ array=(one two three)
$ echo "${array[${#array[@]}-1]}"
three

With this approach, you can pack other parameter expansion operations into the term, e.g. "remove matching prefix pattern" th:

$ echo "${array[${#array[@]}-1]#th}"
ree