in reply to RE: Writing the contents of an array to a file
in thread Writing the contents of an array to a file

print invokes list context: 
[firewheel ~]$ perl
my @list = (1 .. 4);
print STDOUT @list;

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I prefer something like print STDOUT "@list";, which is semantically equivalent to print STDOUT (join($", @array));

Fastolfe is correct, though. This is a scoping issue.

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RE: RE: RE: Writing the contents of an array to a file
by Fastolfe (Vicar) on Sep 28, 2000 at 23:49 UTC
    FYI, $" is to print "@list" as $, is to print @list or print $a, $b, $c 
    @a = qw{ one two };
@b = qw{ tre for };
{
   local $" = "-";
   print "@a @b";        # one-two tre-for
}
{  local $, = "-";
   print @a, @b;         # one-two-tre-for
   local $" = ":";
   print "@a", "@b";     # one:two-tre:for
}

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    Cheers
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      Note also that while each pair of lines of code below produce the same output: 

          print FILE "@array";
    print FILE join $", @array;

    print FILE @array;
    print FILE join $,, @array;

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      they are not equivalent in terms of performance. Only print FILE @array avoids building a potentially huge string in memory before writing. In practice, the speed improvement is usually small (or even negative) but I prefer to allow for huge arrays and avoid the join if I'm just going to write the result to a file and then throw the constructed string away.

      Though I do find appealing the way that using join prevents your code from breaking if you accidentally sneak a scalar context into the mix (typing a "." when you meant a ",", for example).

              - tye (but my friends call me "Tye")
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