Hi, i am working on my regexes, in this case backreferences. I found this code :

This code should find all three letter-doubles. Unfortunately i can't bring it to work, because there is little further explanation. i was hoping someone could give some useful comments about this line of code, maybe give a short example. I have added some code that i wrote , which finds all three-letter words and reports how many times each word occurs.Thanks

$term = 'Dit is het eerste het is niet het laatste Dit';
@woorden = split / /, $term;
@let = grep (length($_)=3,@woorden);
foreach(@let){
 $aantal = $term =~ s/$_//g;
 if($aantal==0){next;}
 print "$_:"."$aantal\n";
       };
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