Re[4]: [PHP] preg_replace: avoiding double replacements

Hello Peter, Hm... I see I need to specify what I'm really doing. Actually, I need to change the letters in the text. It's a famous and ancient crypting method: you divide the alphabet making two parts, then you change the letters of one part with letters for other part (so A becomes N, B becomes O, etc., and vice versa). it works fine and slightly with strtr or str_replace... but only if the text is not in utf-8 and it doesn't contain any non-English letters such as Cyrillic what I need. What my regex does is the following: it sees an A, well it changes it to N; then it goes through the string and sees an N... what does it do? Surely, it changes it back to A! I hoped (in vain) that there exists a modifier preventing this behavior... but it seems that it's false( Thanks! -- With best regards from Ukraine, Andre Skype: Francophile; Wlm&MSN: arthaelon @ yandex.ru; Jabber: arthaelon @ jabber.org Yahoo! messenger: andre.polykanine; ICQ: 191749952 Twitter: m_elensule ----- Original message ----- From: Peter Lind <peter.e.lind@gmail.com> To: Andre Polykanine <andre@oire.org> Date: Tuesday, May 18, 2010, 10:19:51 AM Subject: [PHP] preg_replace: avoiding double replacements On 18 May 2010 09:04, Andre Polykanine <andre@oire.org> wrote: [snip] > Andre Polykanine wrote: >> Hello everyone, >> >> Sorry for bothering you again. >> Today I met a problem exactly described by a developer in users' notes >> that follow the preg_replace description in the manual: >> info at gratisrijden dot nl >> 02-Oct-2009 02:48 >> if you are using the preg_replace with arrays, the replacements will apply as subject for the patterns later in the array. This means replaced values can >> be replaced again. >> >> Example: >> <?php >> $text = >> 'We want to replace BOLD with the <boldtag> and OLDTAG with the <newtag>'; >> >> $patterns >> = array( >> '/BOLD/i', >> '/OLDTAG/i'); >> $replacements >> = array( >> '<boldtag>', >> '<newtag>'); >> >> echo preg_replace >> ($patterns, $replacements, $text); >> ?> >> >> Output: >> We want to replace <b<newtag>> with the <<b<newtag>>tag> and <newtag> with the <newtag> >> >> Look what happend with BOLD. >> >> Is there any solution to this besides any two-step sophisticated trick >> like case changing? >> Thanks! >> Use better regexes: either match for word endings or use a delimiter in your markers (i.e. ###BOLD### instead of BOLD). Regards Peter -- <hype> WWW: http://plphp.dk / http://plind.dk LinkedIn: http://www.linkedin.com/in/plind Flickr: http://www.flickr.com/photos/fake51 BeWelcome: Fake51 Couchsurfing: Fake51 </hype> -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php