Quote and Quote-like Operators
While we usually think of quotes as literal values, in Perl they function as operators, providing various kinds of interpolating and pattern matching capabilities. Perl provides customary quote characters for these behaviors, but also provides a way for you to choose your quote character for any of them. In the following table, a {} represents any pair of delimiters you choose. Non-bracketing delimiters use the same character fore and aft, but the 4 sorts of brackets (round, angle, square, curly) will all nest.
| Customary | Generic | Meaning | Interpolates |
| ” | q{} | Literal | no |
| “” | qq{} | Literal | yes |
| “ | qx{} | Command | yes (unless ” is delimiter) |
| qw{} | Word list | no | |
| // | m{} | Pattern match | yes |
| qr{} | Pattern | yes | |
| s{}{} | Substitution | yes | |
| tr{}{} | Transliteration | no (but see below) |
Note that there can be whitespace between the operator and the quoting characters, except when # is being used as the quoting character. q#foo# is parsed as being the string foo, while q #foo# is the operator q followed by a comment. Its argument will be taken from the next line. This allows you to write:
s {foo} # Replace foo
{bar} # with bar.