1. how to I count the occurrences of word 'the' in a file?

   open my $fh, '<', 'theFile' or die $!;
   
   my $count = 0;
   while( <$fh> ) {
       ++$count while m[the]g;
   }
   print "'the' appeared $count times in 'theFile'";
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2. how to I extract the numeric values in a () sample code:? $extract =~/^\( (\d.+) \)$/

   if( $extract =~/^\( (\d.+) \)$/ ) {
       print "The number was $1";
   }
   else {
       print "The regex didn't match";
   }
   [download]

Um -- (1) would be an infinite loop, without a "g" in the regex. Use:

use strict;

my $count = 0;
while( <DATA> ) {
   print;
    ++$count while m[the]ig;
}
print "'the' appeared $count times in 'theFile'\n";
__DATA__
THis is the dawning of the age of Aquarius.
Good morning Starshine, the earth says hello. The end.
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For #2, simpler code:

my ($extracted_value) = $extract =~/^\( (\d.+) \)$/;
# Will be undef if nothing found.
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     Syntactic sugar causes cancer of the semicolon.        --Alan Perlis

(1) would be an infinite loop, without a "g" in the regex

Indeed, now corrected. I explicitly remove the /i (and accidentally the /g), because it would give wrong results if the OP really mean 'the' and not 'The' or 'THE'.

simpler code: Will be undef if nothing found.

That is no simpler as you still have to handle the possibility of undef.

---

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

how to I count the occurrences of word 'the' in a file?

Per perlfaq4 and with the basic regex \bthe\b to indicate a word boundary as documented in perlre, we get:

my $data = do {local $/; <DATA>};

my $count = () = $data =~ m/\bthe\b/ig;

print $count;

__DATA__
Then I played with the rabbit and the thesaurus. (2)
It was quite the experience. (1)
Seriously, the bunny was the coolest pet in the whole zoo. (3)
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