The important thing to understand (and something that I clearly misunderstood ten years ago -- I still remember the feeling of egg on face) is that there simply is no such thing as a list in scalar context. A "list producing expression used in scalar context" does not produce a list. It just produces a single value, which is the last element in the comma-delimited expression. (That's as near as I can come to describing the right-hand-side.)

So the truth is that this construct:

my $a = ( 10, 20, 30, 40, 50 );

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...is not generating a list in scalar context and then assigning the last element to $a. It's assigning the scalar value 50 to $a, that's it. There's no list, and the entity has a size of one.

B::Deparse's output is interesting when list-producing syntax is used in scalar context. There's no list. :)

perl -MO=Deparse -E '$x = (10,20,30); say $x'

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There you'll see the comma operator at work doing what it's supposed to do in scalar context: throwing away the item on the lefthand, returning the one on the right.


Dave

In reply to Re: Return Value of List-Producing Elements in Scalar Context by davido
in thread Return Value of List-Producing Elements in Scalar Context by pikus

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