What is the proper way to check if a string is empty in Perl

Question

I ve just been using this code to check if a string is empty   if   str                       And also the same with the not equals operator     if   str                       This seems to work  I think   but I m not sure it s the correct way  or if there are any unforeseen drawbacks  Something just doesn t feel right about it

User · Answer

To check for an empty string you could also do something as follows  if   defined  val     val eq             empty

User · Answer

For string comparisons in Perl  use eq or ne   if   str eq                    The    and    operators are numeric comparison operators  They will attempt to convert both operands to integers before comparing them   See the perlop man page for more information

User · Answer

The very concept of a  proper  way to do anything  apart from using CPAN  is non existent in Perl    Anyways those are numeric operators  you should use   if  foo eq       or  if length  foo     0

User · Answer

Due to the way that strings are stored in Perl  getting the length of a string is optimized  if  length  str  is a good way of checking that a string is non-empty  If you re in a situation where you haven t already guarded against undef  then the catch-all for  non-empty  that won t warn is if  defined  str and length  str

User · Answer

As already mentioned by several people  eq is the right operator here   If you use warnings  in your script  you ll get warnings about this  and many other useful things   I d recommend use strict  as well

User · Answer

You probably want to use  eq  instead of        If you worry about some edge cases you may also want to check for undefined   if  not defined  str       this variable is undefined

[perl] What is the proper way to check if a string is empty in Perl?

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