and the use of normal regex match delimiters around that variable when applying the match to another string.

The use of regex match delimiters is not actually necessary when matching against a string as the binding operator provides the context to use the compiled regex. They are needed if doing a default match against $_ without a binding operator.

knoppix@Microknoppix:~$ perl -E '
> $rx  = qr{(\d+)};
> 
> $str = q{ab12ef};
> $_   = q{gh34kl};
> 
> say $1 if $str =~ $rx;
> say $1 if $rx;
> say $1 if m{$rx};
> 
> $_   = q{mn56qr};
> 
> say $1 if $_ =~ $rx;'
12
12
34
56
knoppix@Microknoppix:~$

[download]

I hope this is of interest.

Cheers,

JohnGG

In reply to Re^3: store regex in hash by johngg
in thread store regex in hash by salp

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