while question

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hi, I need to add the values in column 1 together except for the last line, how can i ignore the last line in this context?

open (COM, "2_info.txt");
      open (MEAN, ">" . "/2_mean_info.txt");
       foreach  (<COM>){

last LINE if /^d$/;??

if (/^\d+\.\d+.*/)
    {$value = (split /\|/, $_)[0];}

        $additive_GU_value += $value;
        $num_GU_processed++ ;
              
} # foreach
close (COM);

print "Add = $additive_GU_value\n";
[download]

input

10|
20|
45|
1
[download]

thanks

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Re: while question by davidrw (Prior) on Jun 02, 2005 at 14:42 UTC
with the code above, i see a few different methods: (My preferred method) Match not just on the line starting w/a number, but also having a pipe: `if( /^(\d+\.\d+)\\|/ ){ $additive_GU_value += $1; $num_GU_processed++ ; }` [download] Check the split() to see that it got a 2-element array back. Subtract off the last value. (i don't like this method) `} # foreach $additive_GU_value -= $value; close (COM);` [download] Push the first column to an array, and at the end `pop` the last item before looping through and summing. This innately stores the num_GU_processed, too.	[reply] [d/l] [select]
Re^2: while question by Anonymous Monk on Jun 02, 2005 at 15:00 UTC
thanks for the thoughts i extended the if loop and that seems to work fine cheers	[reply]
Re: while question by Fletch (Bishop) on Jun 02, 2005 at 14:37 UTC
It looks like your valid data lines only match `/^(\d+(?:\.\d))\\|/`, so you want to only add if the line matches. What you've done is unconditionally add whatever was left in `$value` from the last time through your loop. Update:* Also, read `perldoc perlstyle` and look into `perltidy` presuming that's actually how your code is formatted. Better indentation might help you visualize the flow and have helped you catch this. -- We're looking for people in ATL	[reply] [d/l] [select]
Re: while question by cool_jr256 (Acolyte) on Jun 02, 2005 at 14:39 UTC
Hope I understood your problem, but if I did, then the easiest way would be to match for the '\|' which would exclude the last line.... Just a thought..	[reply]
Re: while question by Anonymous Monk on Jun 02, 2005 at 14:34 UTC
the funyy thing is that the answer is wrong if i dont explicity ignore the last line	[reply]