In the regular expression, yes it does. In the replacement expression $n is the n'th capture string in the regular expression. So for s/(x) (y)/$1$2)/ 'x y' gets replaced with 'xy' for example.

Perl is Huffman encoded by design.

In reply to Re^3: Regular Expressions: Removing 'only' single spaces from a string by GrandFather
in thread Regular Expressions: Removing 'only' single spaces from a string by BioBoy

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