in reply to Counting the number of items returned by split without using a named array

Another way that avoids a named array. 

$entries = @{[ split /\s+/ ]};

[download]

Also, split /\s+/ is the similar to as the slightly magical split ' ', except undefs from leading whitespace are suppressed.

In turn, split ' ' is the same as split with no arguments, so you could reduce your code to: 

$entries = @{[ split ]};

[download]

If you don't have leading whitespace, or don't want to count the undef any leading whitespace would produce as an entry.

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal?
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

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Re^2: Counting the number of items returned by split without using a named array
by Anonymous Monk on May 03, 2006 at 13:34 UTC
    My bias goes towards either 
    $entries = @{[ split ]};

    [download]

    or 
    $entries = () = /\S+/g;

    [download]

    as "most elegant".
    It's both sufficiently short, although I'm not sure which one is easier to understand for the uninitiated reader :)
    Just out of curiosity (it doesnt really matter in my case):
    which one would be the more (CPU- and memory-) efficient one?

    I.

[reply]
[d/l]
[select]

      C:\test>p1
our $s = join ' ', 'aa'..'zz';;
cmpthese -3, { 
    split => q[ $_=$s; my $n = @{[ split ]}; ], 
    regex => q[ $_=$s; my $n = () = /\S+/g;  ] 
};;
        Rate regex split
regex  546/s    --  -50%
split 1102/s  102%    --

      [download]

      Assuming I didn't goof on the benchmark split appears to be quicker.

      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal?
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]
[d/l]
        Strange
        perhaps it depends on the length of the input string?
        My attempt shows a different result
        You seem to be under windows - so just for comparison: 
        $ cat a.pl; echo '-----------' ;echo;./a.pl 
#!/usr/local/bin/perl -w
           use Benchmark qw(:all) ;

our $s = join ' ', 'aa'..'zz';;
cmpthese( -3, { 
    split => q[ $_=$s; my $n = @{[ split ]}; ], 
    regex => q[ $_=$s; my $n = () = /\S+/g;  ] 
});

-----------

        Rate regex split
regex  981/s    --  -53%
split 2098/s  114%    --

        [download]

        Hm, now where's the big diff to the other Bench?
        I.
[reply]
[d/l]
      Just out of curiosity (it doesnt really matter in my case): which one would be the more (CPU- and memory-) efficient one?

      It hardly ever matters. As a wild guess I would say that since the former involves doing something and then undoing it and that something is taking a reference, it is more computationally intensive. In case of doubt

      use Benchmark;

      [download]

      I may well (and happily!) prove wrong...

[reply]
[d/l]
        As you wish (or not): 
        $ cat foo.pl ; echo "--------";echo; ./foo.pl 
#!/usr/bin/perl 
##################
use Benchmark qw(:all) ;

sub test1(){
$entries = @{[ split ]};
}

sub test2(){
$entries = () = /\S+/g;
}

$_="This is an example string with several words bla bla bla\n";
$count=1E+7;
timethis ($count, "test1()");
print "------------\n";
timethis ($count, "test2()");


--------

timethis 10000000: 13 wallclock secs (12.37 usr +  0.01 sys = 12.38 CP
+U) @ 807754.44/s (n=10000000)
------------
timethis 10000000:  7 wallclock secs ( 6.66 usr +  0.00 sys =  6.66 CP
+U) @ 1501501.50/s (n=10000000)

        [download]
[reply]
[d/l]
Re^2: Counting the number of items returned by split without using a named array
by blazar (Canon) on May 03, 2006 at 10:57 UTC
[reply]
[d/l]

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