Is there any good book or website where I can learn php regular expressions?

Question

Any recommendations, as I need to learn regular expressions to search for specific string and replace using specific operators. I have looked at the php functions such as preg_match && preg_replace and understood how they work but all I need is to be more familiar with the operators for expressions. Thanks.

Answer 1

learn perl regular expressions as they are universal and you can use them in PHP as well.

Answer 2

PHP supports two sets/libraries, the first is Perl compatible regular expressions or PCRE, which are more modern and practical in use ( preg functions ) as opposed to the POSIX Extended Regular Expressions "standard" which is a tad outdated/ more bare-bones ( ereg functions ) compared to PCRE.

I would recommend going through the perlre tutorial, either use Perl or substitute the Perl methods with PHP ones. Of course Perl Regex engine is more advanced/up to date than the one in the PHP PCRE engine, but the core is pretty much the same.

If you really would like to purchase a book then I would recommend:

• Regular Expressions Cookbook
• Mastering Regular Expressions

The first being more of a cookbook and is relatively new, the second is the definitive guide on regular expressions and covers them in various PCRE implementations and languages.

Good utilities for testing them live/online:

• http://regexpal.com/
• http://www.rubular.com/
• http://www.txt2re.com/

References:

• http://www.regular-expressions.info/quickstart.html
• http://www.regular-expressions.info/reference.html ( Basic )
• http://www.regular-expressions.info/refadv.html ( Advanced )
• http://www.addedbytes.com/cheat-sheets/regular-expressions-cheat-sheet/ ( Cheat sheet )

Answer 3

regular-expressions.info is pretty good too, the quickstart guide is useful. Though can be a little complex

W3Schools is also a good place to look, has a nice list of operators.

Answer 4

http://www.regular-expressions.info that's where i started.... might want to use a regex testing tool too

Answer 5

There is no such thing as PHP regular expressions =P There exists Perl-Compatible and POSIX Extended regular expressions in PHP.

A search on Amazon for regular expressions would list:

1. Mastering Regular Expressions
2. Regular Expressions Cookbook

in that order. Those books are the only books you´ll ever need in this subject.

Answer 6

I'd recommend checking out this site

http://www.gskinner.com/RegExr/

I like it, because you can immediately see what your regular expression matches as you type.