use Regexp::Common;
use Data::Dumper;
use v5.30.0;

my $value = "+a1.2cd";

if ( $RE{num}{int} -> matches($value) ) {
    say "INTEGER patern:\t".$RE{num}{int};
    say $value;
    say "It is Integer";
}elsif ( $RE{num}{real}->matches($value) ) {
    say "REAL patern:\t".$RE{num}{real};
    say $value;
    say "It is Real";
}else{
    say "It is String";
}
[download]

I tried Regexp::Common , but seams to behave weird to me. The code above is saying :

It is Integer

That is documented behavior:

NOT A BUG
 • The various patterns are not anchored. That is, a pattern like "$RE
+{num}{int}"
   will match against "abc4def", because a substring of the subject ma
+tches.
   This is by design, and not a bug. If you want the pattern to be anc
+hored, use
   something like:

     my $integer = $RE{num}{int};
     $subj =~ /^$integer$/ and print "Matches!\n";
[download]


Enjoy, Have FUN! H.Merijn

The documentation explains this.

The various patterns are not anchored. That is, a pattern like $RE {num} {int} will match against "abc4def", because a substring of the subject matches. This is by design, and not a bug. If you want the pattern to be anchored, use something like:

my $integer = $RE {num} {int};
$subj =~ /^$integer$/ and print "Matches!\n";
[download]