You're thinking of the "last index" construct. ghenry is talking about the output numeric format $#. It's a sprintf-style format which perl uses for stringifying numbers.
After Compline,
Zaxo
In reply to Re^2: Is $# still used?
by Zaxo
in thread Is $# still used?
by ghenry
| For: | Use: | ||
| & | & | ||
| < | < | ||
| > | > | ||
| [ | [ | ||
| ] | ] |