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Re: search for nth occurrence of a pattern in a line

by ioannis (Prior)
on May 17, 2006 at 08:56 UTC ( #549965=note: print w/replies, xml ) Need Help??

in reply to search for nth occurrence of a pattern in a line

Here is a solution. The basic idea to count the times we of the found pattern as we scan the string from left to right. Although we can compact the code into 2 short lines, it is shown bellow longer and verbose.

# $n is the nth wanted occurence, as indicated by the question. # $i holds how many times we found the pattern my $str = ',n ,pple , d,y'; my ($n, $i) = 4; $str =~ / , # we are searching for the , pattern (?{ $i++}) # we found it again , increament $i /xgc # retain last occurance on failure for (1..$n); # print position in string print +($n == $i) ? pos($str) - 1 : 'not found';

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