It largely depends from whom you learn. Most people google and run with the first thing google throws up and perl has many, MANY (due to its age) really shitty learning resources. Even the most popular one, the book Learning Perl, has as of its 6th edition (2013), grave flaws and miseducates newbies severely.
Some comment from the position of someone familiar with Modern Perl, which is largely what's practiced on CPAN:
> shift() shifts @_ by default
This is discouraged, precisely because it messes with @_. It has valid uses, but people tend to make sure it's clear from the code why it's used. (Mainly in OO helper stuff.)
> <> iterates over @ARGV
Almost nobody uses that, precisely because it's very unreadable. It only exists for compatibility reasons and was made to serve people used to sed/awk.
> chomp chomps $_
I haven't seen code use chomp in ages. I've never used it myself.
> Messing with @INC changes library search paths, etc.
This is rarely used as well. Mainly only when doing release engineering. It's also most often done via `use lib 'whatever';`.
push(@{$TV{$family}{kids}},"anotherkid");
That is an outdated way to write that. In a decent modern style it would be written like this:
Yes, I think the biggest issue with perl was the devil-may-care culture around it. That was far from the only issue, though. It had (has?) some gratuitous features which are bound to cause hard to find bugs, like implicit conversion of numeric strings to numbers in certain contexts. That particular feature was the reason I chose to learn python in the mid 90s, rather than perl.
> implicit conversion of numeric strings to numbers in certain contexts.
In Perl 6 at least, and to a large degree Perl 5 too, context only "causes" bugs if coders make assumptions that are invalid in Perl.
For example:
say $foo + $bar
adds two numbers. So the context for $foo and $bar is numeric. So Perl coerces them to be numbers. If you didn't mean to add two numbers, don't use a numeric operation such as `+`.
If you want Perl 6 to make sure $foo and $bar are numbers already, then add a type to their declaration:
Some comment from the position of someone familiar with Modern Perl, which is largely what's practiced on CPAN:
> shift() shifts @_ by default
This is discouraged, precisely because it messes with @_. It has valid uses, but people tend to make sure it's clear from the code why it's used. (Mainly in OO helper stuff.)
> <> iterates over @ARGV
Almost nobody uses that, precisely because it's very unreadable. It only exists for compatibility reasons and was made to serve people used to sed/awk.
> chomp chomps $_
I haven't seen code use chomp in ages. I've never used it myself.
> Messing with @INC changes library search paths, etc.
This is rarely used as well. Mainly only when doing release engineering. It's also most often done via `use lib 'whatever';`.
That is an outdated way to write that. In a decent modern style it would be written like this: And with a more modern Perl, this: