=over =item ${^PREMATCH} X<$`> X<${^PREMATCH}> This is similar to C<$`> ($PREMATCH) except that it does not incur the performance penalty associated with that variable. See L above. In Perl v5.18 and earlier, it is only guaranteed to return a defined value when the pattern was compiled or executed with the C

modifier. In Perl v5.20, the C

modifier does nothing, so C<${^PREMATCH}> does the same thing as C<$PREMATCH>. This variable was added in Perl v5.10.0. This variable is read-only and dynamically-scoped. =back