RE: [PHP] Unable to match dollar sign in preg_match

> -----Original Message----- > From: John W. Holmes [mailto:holmes072000@charter.net] > Sent: 24 December 2002 00:44 > > If you want to use some of PHP's special characters in your > expression, Don't you mean "preg's special characters"? Or even "PHP special characters which are also preg special characters", as it's this duality of specialness that leads to the necessity of double-escaping! > such as $, you must escape it twice. For example: > > $matchme = "\$example"; > if (preg_match("/\$example/", $matchme)) { > > will not be matched because PHP interprets the \$ and passes it as $. > Instead, you must do this: > > if (preg_match("/\\\$example/", $matchme)) { This is the main reason I prefer to use *single*-quoted strings whenever possible in preg_ calls -- the above could more legibly be written as: if (preg_match('/\$example/', $matchme)) { This is an instance where I'd even tend to prefer to write single-quoted strings concatenated to bare variables, rather than using double-quoted strings and variable-interpolation: if (preg_match('/\$'.$example.'\./', $matchme)) { rather than if (preg_match("/\\\$$example\\./", $matchme)) { Cheers! Mike --------------------------------------------------------------------- Mike Ford, Electronic Information Services Adviser, Learning Support Services, Learning & Information Services, JG125, James Graham Building, Leeds Metropolitan University, Beckett Park, LEEDS, LS6 3QS, United Kingdom Email: m.ford@lmu.ac.uk Tel: +44 113 283 2600 extn 4730 Fax: +44 113 283 3211