How to use preg_match to extract data?

问题

I am pretty new to the use of preg_match. Searched a lot for an answer before posting this question. Found a lot of posts to get data based on youtube ID etc. But nothing as per my needs. If its silly question, please forgive me.

I need to get the ID from a string with preg_match. the string is in the format

[#1234] Subject

How can I extract only "1234" from the string?

回答1:

One solution is:

\[#(\d+)\]

This matches the left square bracket and pound sign [#, then captures one or more digits, then the closing right square bracket ].

You would use it like:

preg_match( '/\[#(\d+)\]/', '[#1234] Subject', $matches);
echo $matches[1]; // 1234

You can see it working in this demo.

回答2:

You can try this:

preg_match('~(?<=\[#)\d+(?=])~', $txt, $match);

(?<=..) is a lookbehind (only a check)

(?=..) is a lookahead

回答3:

Your regular expression:

preg_match('/^\[\#([0-9]+)\].+/i', $string, $array);

回答4:

That's a way you could do it:

<?php
$subject = "[#1234] Subject";
$pattern = '/^\[\#([0-9]+)/';
preg_match($pattern, $subject, $matches);

echo $matches[1]; // 1234
?>

回答5:

To get only the integer you can use subpatterns http://php.net/manual/en/regexp.reference.subpatterns.php

 $string="[#1234] Subject";
 $pattern="/\[#(?P<my_id>\d+)](.*?)/s";
 preg_match($pattern,$string,$match);
 echo $match['my_id'];

来源：https://stackoverflow.com/questions/18035478/how-to-use-preg-match-to-extract-data

标签

php

regex

preg-match