Re^3: Conditional initialization of my-variables

Bod, I suggest you consider dropping your "major exception" in favour of LanX's excellent advice. That is, I prefer LanX's:

$input //= 1;  # default if undefined
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to your:

$input = 1 unless defined $input;
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See also:

Set default values with the defined-or operator (Effective Perler)
How to set default values in Perl (perlmaven)
Perl Best Practices (reserve postfix if for flow-of-control)

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Re^4: Conditional initialization of my-variables by LanX (Saint) on Apr 08, 2023 at 12:57 UTC
> How to set default values in Perl Gabor is mixing two cases in his article, defaulting undef values defaulting missing values (like with the hashes) But doesn't give an example for missing values in arrays. TIMTOWTDI, alas not very DRY `DB<30> x @_ 0 1 1 2 DB<31> x ($a,$b,$c,$d) = (@_, ("D1".."D4")[@_..3]) 0 1 1 2 2 'D3' 3 'D4' DB<32>` [download] or `DB<32> @DEF= ("D1".."D4") DB<33> x ($a,$b,$c,$d) = (@_, @DEF[@_..$#DEF]) 0 1 1 2 2 'D3' 3 'D4' DB<34>` [download] edit or `use v5.12.0; use warnings; use Data::Dump qw/pp dd/; sub test { my ($x, $y, $z) = ( @_, ("X","Y","Z")[@_..42] ); pp ($x, $y, $z); } test(1..$_) for 0..3` [download] --> `("X", "Y", "Z") (1, "Y", "Z") (1, 2, "Z") (1, 2, 3)` [download] Cheers Rolf _{(addicted to the 𐍀𐌴𐍂𐌻 Programming Language :) Wikisyntax for the Monastery}	[reply] [d/l] [select]

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Re^4: Conditional initialization of my-variables
by LanX (Saint) on Apr 08, 2023 at 12:57 UTC

> How to set default values in Perl

Gabor is mixing two cases in his article,

defaulting undef values
defaulting missing values (like with the hashes)

TIMTOWTDI, alas not very DRY

  DB<30> x @_
0  1
1  2
  DB<31> x ($a,$b,$c,$d) = (@_, ("D1".."D4")[@_..3])
0  1
1  2
2  'D3'
3  'D4'
  DB<32>
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  DB<32> @DEF= ("D1".."D4")

  DB<33> x ($a,$b,$c,$d) = (@_, @DEF[@_..$#DEF])
0  1
1  2
2  'D3'
3  'D4'
  DB<34>
[download]

edit

use v5.12.0;
use warnings;
use Data::Dump qw/pp dd/;


sub test {
    my ($x, $y, $z) =
      ( @_,
        ("X","Y","Z")[@_..42]
      );

    pp ($x, $y, $z);
}

test(1..$_) for 0..3
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("X", "Y", "Z")
(1, "Y", "Z")
(1, 2, "Z")
(1, 2, 3)
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Cheers Rolf
_{(addicted to the 𐍀𐌴𐍂𐌻 Programming Language :)

Wikisyntax for the Monastery}

[reply]
[d/l]
[select]