Re: How to differentiate an empty array from an unitialized one?

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Re^2: How to differentiate an empty array from an unitialized one? by Anonymous Monk on Jul 09, 2018 at 08:07 UTC
Iirc Split can return undef depending on regex capture groups	[reply]
Re^3: How to differentiate an empty array from an unitialized one? by haukex (Archbishop) on Jul 09, 2018 at 08:55 UTC
Split can return undef depending on regex capture groups Yes, that's correct, for example `split( /(x)\|(y)/, "axbyc" )` yields `("a", "x", undef, "b", undef, "y", "c")`. It's also documented at the bottom of split.	[reply] [d/l] [select]
Re^2: How to differentiate an empty array from an unitialized one? by Anonymous Monk on Jul 09, 2018 at 03:57 UTC
Indeed, it would be incorrect for Perl to consider an uninitialized value to be an empty string, for much the same reason why, in SQL, `NULL` is not an empty string.	[reply]
Re^3: How to differentiate an empty array from an unitialized one? by haukex (Archbishop) on Jul 09, 2018 at 09:13 UTC
it would be incorrect for Perl to consider an uninitialized value to be an empty string That is quite incorrect. Perl's undef (the default value for uninitialized scalars) evaluates to an empty string (or zero in numeric context). If warnings are enabled, this will usually warn, but only to indicate that the programmer may have made a mistake, not because it's inherently wrong.	[reply]
Re^3: How to differentiate an empty array from an unitialized one? by Anonymous Monk on Jul 09, 2018 at 08:07 UTC
Perl does exactly that... The question isnt about arrays	[reply]