problem with regex

[olaf]

Hallo,

found this simple pattern on internet:

$test = "gooogle";

if (preg_match("(.)\1{2,}", $test)) {
	echo "bad";
}

after having a look on different regex guides i learned that
(.) = every char/digit/sign
\1 = store the match before
{2,} = more then 2 chars/digits...

but it will not work, whats wrong?

[Weedpacket]

You don't say what's happening instead of what it should; but you are missing expression delimiters.

/(.)\1{2,}/

Oh, and by the way; you'll either want to use single quotes or \1. Otherwise PHP will interpret \1 as an escape sequence for ASCII character 001.

[olaf]

Hallo,

Thanks both suggestions together gives the result in need. In understand why i need the double backslash but what about the slashes ? I saw them in other patterns but what are they doing?

[Weedpacket]

Those are the expression delimiters, and act as quotes around the regexp, separating it from any modifiers (i, s, x, e, etc.) that may follow it. Part of the reason is historical (sed and later Perl delimited regexps this way). / is traditional, but if you're going to be using that character in your regexp then it's nice to know that just about any non-alphanumeric character can be used.

(Another answer I've given that looks at it from the other end is this one.