Re^5: Conditional initialization of my-variables

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>
[download]

Cheers Rolf
_{(addicted to the 𐍀𐌴𐍂𐌻 Programming Language :)

Wikisyntax for the Monastery}

Comment on Re^5: Conditional initialization of my-variables Download Code

Replies are listed 'Best First'.
Re^6: Conditional initialization of my-variables by kcott (Archbishop) on Apr 08, 2023 at 19:49 UTC
"When dealing with empty strings, I'd rather check `length`" I concur; however, for anyone using a version prior to `v5.14.0`, a few things to note: Prior to `v5.12.0`, the operand needed to be defined to avoid a "Use of uninitialized value" warning. [length() doco for v5.10.1] `v5.12.0` allowed the operand to be `undef` (see "perl5120delta: Other potentially incompatible changes"). However, there was a bug (see next point). [length() doco for v5.12.0] `v5.14.0` fixed that bug (from last point): "perl5140delta: Syntax/Parsing Bugs". — Ken	[reply] [d/l] [select]

Replies are listed 'Best First'.

Re^6: Conditional initialization of my-variables
by kcott (Archbishop) on Apr 08, 2023 at 19:49 UTC

"When dealing with empty strings, I'd rather check length"

I concur; however, for anyone using a version prior to v5.14.0, a few things to note:

Prior to v5.12.0, the operand needed to be defined to avoid a "Use of uninitialized value" warning.
[length() doco for v5.10.1]
v5.12.0 allowed the operand to be undef (see "perl5120delta: Other potentially incompatible changes"). However, there was a bug (see next point).
[length() doco for v5.12.0]
v5.14.0 fixed that bug (from last point): "perl5140delta: Syntax/Parsing Bugs".

— Ken

[reply]
[d/l]
[select]