regular expression basic

first i want some one to give me a lesson on regular expression in general no links please

second i wnt a regexp code for following

• Validate a youtube url eg:- http://www.youtube.com/watch?v=<<<<VIDEO_ID>>>>
• Validate a image url ending with jpeg jpg bmp png
• Validate a name fiels containing A-Z 0-9 <space> - and _

 

You can find this website very helpful in finding the regex you need:

http://regexlib.com/

Peace,

 

I think this free tool is a great way to learn regex
http://www.ultrapico.com/ExpressoDownload.htm

it has a good tutorial too

 

although i said no links you ppl gave me links k thats still fine

now what about the solution to 2,3

 

First, I suggest being a little bit more humble. We're not your servants. You ask questions, we try to help. That the help doesn't quite fulfill your demands, is to be expected. Forums like these are very dynamic, and the help you get, while often very good, will normally try to make you fend for yourself - we're not here to do the job for you, but we do provide helpful hint, links and suggestions as to how you can do it yourself.

 

firstly sorry if it was rude i an sorry but u without any reply(solution) talking all that.....

any solution ppl

 

ifound this url http://regexlib.com/UserPatterns.aspx?authorId=4f1e9e8d-d9fa-4221-ac16-ee9534263d28
but can you give me the php code

validate image ^(http\:\/\/[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}(?:\/\S*)?(?:[a-zA-Z0-9_])+\.(?:jpg|jpeg|gif|png))$
validate youtube (\"http:\/\/www\.youtube\.com\/v\/\w{11}\&rel\=1\")

 

any reply...................