Sams Teach Yourself Perl in 24 Hours

Q&A

Q1:	Are substr, index, and rindex really necessary? Why do they exist when regular expressions can be used for most of those operations?
A1:	First, regular expressions for simple string searches are generally slower than index and rindex. Second, writing substitution expressions for fixed-character positions with regular expressions can be messy; substr is a much more elegant solution sometimes. Third, Perl is a rich language: Use what you like; you have plenty of choices.
Q2:	What happens with substr (or index or rindex) if I specify an index that's beyond the end of the scalar?
A2:	One nice thing about computers is that they're consistent and have limitless amounts of patience. With questions like "What happens if I…?" sometimes just trying ...