Writing it like this (using array slice instead of scalar) (deefering an array-reference just to get one element) is bad.

Why? Simple, it looks too complex.

The bottomline is that you should use $array_reference->[index] instead of @array_reference[$index]. If you want more information about references then you shold read: `perldoc perlreftut` and/or `perldoc perlref` and/or `perldoc perldsc`.(updated)

Here is a possible mis-interpretation of the code.


One can think that the array-reference stored in $record[0] is being de-referenced and that that array is printed.

Ofcourse this is impossible, since $record belongs to the foreach loop, so must be a scalar, and therefor $record[0] can never refer to the first element in this 'array', but someone that does not has that much knowledge about Perl might see it that way... (if it would refer to it it has to be $record->[0])

And if you do that, you might be confusing a (new) Perl-user, which is not a good thing...

For the part of wasting memory, I do not think that foreach $record (@x) uses more memory then foreach (@x).

Unfortunally I do not know what happends when this code is executed (that is, what happends internally). But one possibility would be that $record is replaced with the actual variable of @x... (since it is an alias, every modification of $record will modify the element in the array!). This could be implemented in Perl by using a C-pointer, which would mean you are only wasting a few bytes .

Update: Some mis-interpreatations... (a post above confused me by talking about an array slice, which is not correct).

In reply to Re: Using aliases in for loops or not? by Animator
in thread Using aliases in for loops or not? by jkva

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