in reply to Re^3: Conditional initialization of my-variables
in thread Conditional initialization of my-variables

Careful! Many things are false in Perl, like 0 or ""

Oh yes - care is needed. But very often that's exactly what I want.

A common use case is query strings from HTML forms with checkboxes. The query string will have the key with no value. So if that's decoded into a Perl hash, the hash will be defined and the key exists but I want it to return false as it is an empty string.

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Re^5: Conditional initialization of my-variables
by LanX (Saint) on Apr 08, 2023 at 18:24 UTC
    When dealing with empty strings, I'd rather check length

    Edit

      DB<13> p "false" unless "0"
false
  DB<14> p "false" unless 0
false
  DB<15> p "false" unless length "0"

  DB<16> p "false" unless length undef
false
  DB<17> use warnings; length undef

  DB<18> p "false" unless length ""
false
  DB<19>

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    Cheers Rolf
    (addicted to the 𐍀𐌴𐍂𐌻 Programming Language :)
    Wikisyntax for the Monastery

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