in reply to Re: Get even postion elements in an array
in thread Get even postion elements in an array

Why not be LESS cryptic, e.g.:- 
my $flipflop = 1;
my @result = grep { $flipflop = not $flipflop; }, @input;

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Re^3: Get even postion elements in an array
by LanX (Saint) on Nov 16, 2010 at 15:52 UTC
    I prefer reusable idioms.

    Here not is indeed more readable, but it won't produce 0 for false, which could be counterintuitive in other cases.

    $flipflop needs to be declared, while $a (and $b) is already global as part of the sort idiom, which is a similar case of using a code block.

    $a=1;
my @result = grep { $a = not $a }, @input;

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    At the end it's a matter of taste. ^= is shorter, = not is clearer, but =1- can equally be used in most other languages, making it an universally understood idiom.

    Cheers Rolf

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      Reusable idioms are an open block to your thinking. They are not the same as reusable code. '' is just as false as 0 and is often preferable -- for example, a routine returns or sets a scalar by reference originating from a unix exit code, 0 being unix success, so '' is the best value for "i had to abort earlier than that" $a is not a global, it's a special variable for use in sort blocks, that shouldn't be abused especially by habit -- one day a sort routine will come back to bite you in the bottom. Are you trying to say that not declaring locally and instead using global variables is a virtue? Many here will disagree.

      One world, one people

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