passing anonymous empty array reference to subroutine

Special_K has asked for the wisdom of the Perl Monks concerning the following question:

How can I pass a reference to an anonymous empty array to a subroutine? Here is how I can pass an anonymous empty array to a subroutine:

&foo(qw());
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Now how can I do the same with a reference to an anonymous empty array? I tried this:

&foo(\qw());
[download]

but that didn't work.

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Re: passing anonymous empty array reference to subroutine by choroba (Cardinal) on Apr 02, 2015 at 17:05 UTC
Use square brackets: `foo([]);` [download] See References for details. لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ	[reply] [d/l]
Re: passing anonymous empty array reference to subroutine by AnomalousMonk (Archbishop) on Apr 02, 2015 at 17:21 UTC
... pass an anonymous empty array to a subroutine: `&foo(qw());` A bit OT: I would say a better (because simpler) way to do this would be: `foo();` What would be the purpose of the empty `qw()` call? BTW: I would also advise against using `&` sigils for function calls in "modern" (i.e., post-4.xx version) Perl code; they will usually do no harm, but may introduce subtle bugs in certain cases (usually involving Prototypes — but let's just not involve prototypes!). Give a man a fish: `<%-(-(-(-<`	[reply] [d/l] [select]
Re: passing anonymous empty array reference to subroutine by vinoth.ree (Monsignor) on Apr 02, 2015 at 20:01 UTC
Hi, Here is how I can pass an anonymous empty array to a subroutine: &foo(qw()); Here you are not passing anything. So obviously in function `foo()` `@_` will be empty, it does not mean you are passing anonymous empty array. If you think you are passing anonymous empty array, it should be a first element in `@_`array, print as `$_[0]` you will get 'undef', as suggested by choroba use square bracket [] to pass empty anonymous array, then `print $_[0]` in `foo()` you will get a refernce to a anonymouse array as `[]` *All is well. I learn by answering your questions...*	[reply] [d/l] [select]
Re: passing anonymous empty array reference to subroutine by Anonymous Monk on Apr 06, 2015 at 12:27 UTC
How about, within the function, if the parameter-value received is `undef`, replace it with an empty-array ref and proceed?	[reply]