Did you read Symbolic-Unary-Operators?

$ perl -MO=Deparse -e 'print -"asdf"' print '-asdf'; -e syntax OK
If the operand is an identifier, a string consisting of a minus sign concatenated with the identifier is returned.
$ perl -MO=Deparse -e 'print -"1asdf"' print -1; -e syntax OK
If, however, the string begins with a non-alphabetic character (excluding "+" or "-"), Perl will attempt to convert the string to a numeric and the arithmetic negation is performed.
$ perl -MO=Deparse -e 'print -"-1asdf"' print '+1asdf'; $ perl -MO=Deparse -e 'print -"+1asdf"' print '-1asdf'; -e syntax OK
Otherwise, if the string starts with a plus or minus, a string starting with the opposite sign is returned.
--
seek $her, $from, $everywhere if exists $true{love};

In reply to Re^3: " - " in the syntax by puudeli
in thread " - " in the syntax by manish.rathi

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