Because people tend to confuse defined and exists with array-elements. Especially when using delete on array-elements. ¹

We had recently a discussion covering this, see Re^3: extracting a list element ( 'delete @array' explained) and connected thread.

> In my situation the numerical keys ($elementIndex) are not contiguous

Personally I think if you really know what you are doing, you should just silence this warning.

NB: But sparse arrays with gaps of non-existing elements are normally more efficiently implemented with hashes.²

Cheers Rolf
(addicted to the Perl Programming Language :)
see Wikisyntax for the Monastery

updates

¹) and because Data::Dumper is kind of lying about non-existing elements.

²) and hashes have the advantage that the number of existing keys is readily available. The length of an array with gaps OTOH is of no help, especially because after a delete all non-existing entries will be truncated from the end.

In reply to Re: Using exists to check element in array by LanX
in thread Using exists to check element in array by david

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