需要一些正则表达式的帮助（php）

Question

For example, I have the following code :

$string  = "adf  gggg  eere value aaaa bbb (10) value 
ddttt ggg www (20) value ddttt ggg www dddd (40) ";
preg_match("/(value).*(\(\d+\))/is", $string, $result);
var_dump($result[2]); // outputs 40.

I'm trying to get the first value (10). The code above outputs 40 which makes sense, but not what I want. The string pattern is : word "value", then a number of any characters, then "(", integer, ")". It seems that I'm missing something obvious... I haven't worked too much with regular expressions, but I believe it can be solved somehow with ?<!value , no luck so far though.

Thanks for any help.

Answer 1

.* is greedy, so it will match as many characters as possible, you want .*? which will match the minimum characters needed to complete the match:

/(value).*?(\(\d+\))/

Answer 2

What's wrong with your regex is that .* is greedy, and tries to matchs as many letters as possible.

preg_match("#value.*?\((\d+)\)#is", $string, $result);

But you can make it faster by using a negative class:

preg_match("#value[^(]+\((\d+)\)#is", $string, $result);

Answer 3

.*?value.*?\((\d+)\).*

Being *? a reluctant match.