Re: idea about negative indexed array keys

[Greg Wooledge]

On Fri, Mar 12, 2021 at 05:11:19PM -0500, Eli Schwartz wrote:
> On 3/12/21 4:58 PM, Alex fxmbsw7 Ratchev wrote:
> > i saw, ${arr[-1]} == syntax error
> > 
> > what about implenting it, -0 is the last -1 is the second last etc
> > 
> > such negative values are already in ${..:<>:<>} implented, as a good small
> > statement for the same style
> 
> How did you accomplish the task of getting a syntax error for this? I
> managed it with:
> 
> $ declare arr=(foo bar baz "syntax error")
> $ echo "${arr[-1]}"; echo "${arr[-2]}"
> syntax error
> baz

unicorn:~$ bash-4.1 -c 'a=(a b c); echo "${a[-1]}"'
bash-4.1: a: bad array subscript

unicorn:~$ bash-4.2 -c 'a=(a b c); echo "${a[-1]}"'
c

Is that close enough?