Re: Print Vs Return In a Subroutine

[JavaFan]

print prints its argument(s) to the current filehandle. return returns its argument(s) to the caller of the sub.

The latter is likely to be faster. But they're doing to totally different things, so it's comparing apples with manholes.

[aaron_baugher]

My guess was that the original poster was trying to ask if it's faster to print within a subroutine or to return a value and then print it. My benchmark says that it's considerably faster to go ahead and print something right away, than to return it and print it. I suppose that's because calling the subroutine in void context allows some work to be optimized away. Of course, we're still comparing two things that are extremely fast, likely faster than almost anything else in a slow program, so it's unlikely that "optimizing" in this way would ever gain anything noticeable in a real-world situation.

bannor:~/work/perl/monks$ cat 962552.pl
#!/usr/bin/env perl
use Modern::Perl;
use Benchmark qw(:all);

cmpthese( 10_000_000, {
        'return it' => \&returnit,
        'print it'  => \&printit,
});

# printing to STDERR so I can redirect to /dev/null
# and still see the benchmark results

sub returnit {
    print STDERR _returnit();
}

sub _returnit {
    'foo';
}

sub printit {
    _printit();
}

sub _printit {
    print STDERR 'foo';
}
bannor:~/work/perl/monks$ perl 962552.pl 2>/dev/null
               Rate return it  print it
return it 1298701/s        --      -24%
print it  1703578/s       31%        --