I certainly do not want to be nitpicking with you, but it seems to me that deleting an array element does not exactly sets it to undef,
@a = 1..3;;
pp \@a;;
[1, 2, 3]

delete $a[1];;
pp \@a;;
[1, undef, 3]

[download]

Close enough for me :)

but rather to "empty slot".... I have no idea of what the difference is.

A Perl array consists of a C array of pointers to scalars.

delete sets the value of the C pointer to 0; and the debugger reports that as "Empty slot"; but in all other circumstances is detected and reported as undef.

If you manually set the value of an array element to undef, then the C array pointer is set to point to the undef, which is a static pointer value that is defined to be undefined :)

It does not make a practical difference for the programmer

Agreed!

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority". I'm with torvalds on this
In the absence of evidence, opinion is indistinguishable from prejudice. Agile (and TDD) debunked

In reply to Re^3: pruning of empty arrayrefs in nested array by BrowserUk
in thread pruning of empty arrayrefs in nested array by building_arch

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