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Re: Why no warnings for 1 in void context?

by Not_a_Number (Prior)
on Jul 16, 2005 at 17:03 UTC ( [id://475481]=note: print w/replies, xml ) Need Help??


in reply to Why no warnings for 1 in void context?

A scalar constant in a void context will result in a warning, unless this constant evaluates to a numeric value of 1...

Actually, the same is true of zero:

% perl -wce 0 -e syntax OK

Given dave_the_m's explanation above, is this to allow:

0 until ....

??

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Re^2: Why no warnings for 1 in void context?
by tlm (Prior) on Jul 17, 2005 at 12:58 UTC

    Actually, the same is true of zero:

    % perl -wce 0 -e syntax OK

    Yes, thank you, and also of undef and (), and of any list whose elements are the scalars already identified; e.g.:

    % perl -wce '( 1, 0, undef, , "di foo", "ds bar", "ig baz" )' -e syntax OK

    Given dave_the_m's explanation above, is this to allow:

    0 until ....
    ??

    Reading between the lines, I gather that you are attaching some significance to the boolean value of the constant in question. I did too on a first reading, but then I realized that it is the boolean value of what follows the while or until that matters. I.e.,

    1 while some_condition_with_side_effects;
    has the same effect as
    0 while some_condition_with_side_effects;

    the lowliest monk

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