use 5.020; use strict; use warnings; sub saeaoagr () { print "foo"; qr/x/; } # Those are the most popular say ("fee" =~ s/e/o/gr . "bar"); say ("fee" =~ s!e!o!gr . "bar"); say ("fee" =~ s|e|o|gr . "bar"); say ("fee" =~ s{e}{o}gr . "bar"); say ("fee" =~ s(e)(o)gr . "bar"); say ("fee" =~ s[e][o]gr . "bar"); return m/e/gr; return m!e!gr; return m|e|gr; return m{e}gr; return m(e)gr; return m[e]gr; # Those have syntactic significance say ("fee" =~ s?e?o?gr . "bar"); say ("fee" =~ s'e'o'gr . "bar"); # ' # quote to fix # Those are valid, but infrequent (and weird) say ("fee" =~ s"e"o"gr . "bar"); # " # quote to fix say ("fee" =~ s aeaoagr . "bar"); say ("fee" =~ s#e#o#gr . "bar"); # Those must not be confused with the previous two say ("fee" =~ saeaoagr . "bar"); # calls saeaoagr() say ("fee" =~ s #e#o#gr that's a comment, not a regex (e)(o)gr . "bar"); # and here's the regex.