I'm trying to get the string hello world.
This is what I've got so far:
$file = "1232#hello world#";
preg_match("#1232\#(.*)\##", $file, $match)
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1Could you give more examples of strings that you're trying to match?Ja͢ck– Ja͢ck2012-11-26 02:57:55 +00:00Commented Nov 26, 2012 at 2:57
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sorry about the double backslash. i thought i need to put another backslash to make it visible.Kevin King– Kevin King2012-11-27 06:39:05 +00:00Commented Nov 27, 2012 at 6:39
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5 Answers
It is recommended to use a delimiter other than # since your string contains #, and a non-greedy (.*?) to capture the characters before #. Incidentally, # does not need to be escaped in the expression if it is not also the delimiter.
$file = "1232#hello world#";
preg_match('/1232#(.*?)#/', $file, $match);
var_dump($match);
// Prints:
array(2) {
[0]=>
string(17) "1232#hello world#"
[1]=>
string(11) "hello world"
}
Even better is to use [^#]+ (or * instead of + if characters may not be present) to match all characters up to the next #.
preg_match('/1232#([^#]+)#/', $file, $match);
answered Nov 26, 2012 at 2:34
Michael Berkowski
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Comments
Use lookarounds:
preg_match("/(?<=#).*?(?=#)/", $file, $match)
Demo:
preg_match("/(?<=#).*?(?=#)/", "1232#hello world#", $match);
print_r($match)
Output:
Array
(
[0] => hello world
)
Test it here.
3 Comments
Ωmega
preg_match("/(?<=#)[^#]*(?=#)/", $file, $match); works as well
Krzysztof Jarosz
could you please explain a just a little how that works? It is ok, but I can't understand that (?<=#) ... thank you.
Ωmega
@KrzysztofJarosz -
(?<=#) is a positive lookbehind and means that match is preceded by #, while (?=#) is a positive lookahead and means that match is followed by #. For more information about lookaround zero-length assertions see regular-expressions.info/lookaround.htmlIt looks to me like you just have to get $match[1]:
php > $file = "1232#hello world#";
php > preg_match("/1232\\#(.*)\\#/", $file, $match);
php > print_r($match);
Array
(
[0] => 1232#hello world#
[1] => hello world
)
php > print_r($match[1]);
hello world
Are you getting different results?
Comments
preg_match('/1232#(.*)#$/', $file, $match);
Comments
What if you want the delimiter to also be included in the array, this would be more usefull for preg_split where you might not want each array element to begin and end with the delimiters, the example im about to show would would include the delimeters inside the array values. this would be what you would need preg_match('/\#(.*?)#/', $file, $match); print_r($match); this would output array(
[0]=> #hello world#
)
Comments
