#!/usr/bin/perl
use warnings;

for my $i (1..5)
{
   $x+1; # here just to throw an error to STDERR
   print "$i\n";
}

__END__
Useless use of addition (+) in void context at C:\Projects_Perl\testing\demoStdErrorTiming1.pl line 6.
Name "main::x" used only once: possible typo at C:\Projects_Perl\testing\demoStdErrorTiming1.pl line 6.
Use of uninitialized value $x in addition (+) at C:\Projects_Perl\testing\demoStdErrorTiming1.pl line 6.
Use of uninitialized value $x in addition (+) at C:\Projects_Perl\testing\demoStdErrorTiming1.pl line 6.
Use of uninitialized value $x in addition (+) at C:\Projects_Perl\testing\demoStdErrorTiming1.pl line 6.
Use of uninitialized value $x in addition (+) at C:\Projects_Perl\testing\demoStdErrorTiming1.pl line 6.
Use of uninitialized value $x in addition (+) at C:\Projects_Perl\testing\demoStdErrorTiming1.pl line 6.
1
2
3
4
5

##</code><code>##

#!/usr/bin/perl
use warnings;
$|=1;               ### BIG DEAL HERE ### Unbuffers STDOUT

for my $i (1..5)
{
   $x+1; #here just to throw an error to STDERR
   print "$i\n";
}

__END__
Useless use of addition (+) in void context at C:\Projects_Perl\testing\demoStdErrorTiming2.pl line 7.
Name "main::x" used only once: possible typo at C:\Projects_Perl\testing\demoStdErrorTiming2.pl line 7.
Use of uninitialized value $x in addition (+) at C:\Projects_Perl\testing\demoStdErrorTiming2.pl line 7.
1
Use of uninitialized value $x in addition (+) at C:\Projects_Perl\testing\demoStdErrorTiming2.pl line 7.
2
Use of uninitialized value $x in addition (+) at C:\Projects_Perl\testing\demoStdErrorTiming2.pl line 7.
3
Use of uninitialized value $x in addition (+) at C:\Projects_Perl\testing\demoStdErrorTiming2.pl line 7.
4
Use of uninitialized value $x in addition (+) at C:\Projects_Perl\testing\demoStdErrorTiming2.pl line 7.
5