using regular expression for preg replace

Question

i wanna to know the best regular expression to replace this string with the vid_id in it

$code = '&lt;object width=&quot;420&quot; height=&quot;345&quot;&gt;<br />
    &lt;param name=&quot;movie&quot; value=&quot;http://www.badoobook.com/clips/swf/player.swf&quot;&gt;&lt;/param&gt;<br />
    &lt;param name=&quot;allowFullScreen&quot; value=&quot;true&quot;&gt;&lt;/param&gt;&lt;param name=&quot;flashvars&quot; value=&quot;vid_id=100226&amp;MainURL=http%3A%2F%2Fwww.bado  obook.com%2Fclips&amp;em=1&quot;&gt;<br />
    &lt;embed src=&quot;http://www.badoobook.com/clips/swf/player.swf&quot; flashvars=&quot;vid_id=100226&amp;MainURL=http%3A%2F%2Fwww.  badoobook.com%2Fclips&amp;em=1&quot; type=&quot;application/x-shockwave-flash&quot; allowScriptAccess=&quot;always&quot; width=&quot;420&quot; height=&quot;345&quot; allowFullScreen=&quot;true&quot;&gt;&lt;/embed&gt;&lt;/object&gt;'
$regular = '';
$code = preg_replace($regular ,'$1' , $code);
echo $code;

the vid id in this code is

value="vid_id=100226&

thanks for helping

the big proplem that i face is the < i think there is some special things in regulat expression to read it , and i don't know it — Moustafa Abdul Kareem, Mar 24 '12 at 21:10

score 2 · Answer 1 · answered Mar 24 '12 at 21:09

2

use this regular expression:

vid_id=(\d+)

answered Mar 24 '12 at 21:09

dotoree

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this will give me the id , but the thing i want is to replace the whole code with the nember – Moustafa Abdul Kareem Mar 24 '12 at 21:20

score 1 · Accepted Answer · answered Mar 24 '12 at 22:44

You could use a Regex like this:

(?<=vid_id=)\d+

This uses a positive lookbehind to match any number of digits that are preceded by the literal character set "vid_id="

Here it is again with RegexBuddy comments:

@"
(?<=          # Assert that the regex below can be matched, with the match ending at this position (positive lookbehind)
   vid_id=       # Match the characters “vid_id=” literally
)
\d            # Match a single digit 0..9
   +             # Between one and unlimited times, as many times as possible, giving back as needed (greedy)
"

You have tagged your question with both php and asp.net so i'm not sure which implementation you are after. Here is both:

Asp.Net (C#)

Regex.Replace(@"...uot;vid_id=100226&amp;...", @"(?<=vid_id=)\d+", "[Your value here]")

php

echo preg_replace("(?<=vid_id=)\d+", "[Your value here]", "...uot;vid_id=100226&amp;...");

using regular expression for preg replace

2 Answers2