preg_replace vs str_replace

[micmania1]

I have a forum which at the moment, has no bbcode. All messages are stored using htmlspecialchars(). The only formatting it does is, parses each message, and replaces '\n' with '<br />'

 

Now I am looking into creating bbcode functions and the tutorials on creating bbcode functions use preg replace.

 

Is there a reason preg_replace is better than str_replace?

 

Can somebody give me examples of when each should be used over the other?

 

Any info is appreciated.

[micah1701]

preg_replace is geared towards using Perl Regular Expressions.

 

where as str_replace is for simple search and replace functions.

[micmania1]

So there is no reason why, at this moment in time, I need to work out what all the nasty looking preg_replace patterns mean?

[micah1701]

probably not...but when you do, ask questions in this sites Regex board. There are a few geniuses that keep an eye on those threads who always post awesome advice (I'm not one of them)

[Spaceman-Spiff]

By using regex, you can do pattern matching. It's a much more powerful tool than simple str_replace. Some bb codes can be replaced directly using str_replace, for example for [ b ] or [ /b ] to < b > and < /b >.

 

But for something more complex, like involving attributes, you will need to use regex. For example [ url=http://urllink.com ] text [ /url ]. A simple str_replace won't do.