Problem in searching using preg_match()

[samannoychatter]

I want to search the numbes 0710 or 7109 or 1090 or 109 or 071 or 710 using preg_match .

I have tried the below codes but its not working always returning false .

Please help me.. where i am going wrong. What should be the correct coding using preg_match.

if(preg_match("/(0710)|(7109)^(1090)*(109)-(071)#(710)/",$rollno)==false)
		{
		$GLOBALS['err']="YOU ARE NOT A STUDENT . PLEASE FILL THE ROLL NO. CORRECTLY.";
		main();
		exit();
		}

[sfullman]

the ^ character is the one giving you the problem. preg is looking for something^something, and there can be no something before ^ since ^ represents the beginning of the string. If the rollno is a field dedicated to just the rollno and not a text/paragraph, I doubt you need it

the simplest based on your post would be

0710|7109|1090|109|071| 710

add either * (maybe) or + required if you need to further constrain the result:

(0710[0-9]+)|(7109[0-9]+)|(109[0-9]*)|(071)|(710)

I'm thinking you probably want to use + as I did for 0710

since students may use a space or dash in between, it's best to evaluate like this:

if(!preg_match( [epxression above], preg_replace('/[^{0-9]/','',$rollno))){}
//error state
}

[samannoychatter]

I would like to know few things. 1st what is the use of [0-9] and + and also * . Is | used as separator??
in the below code??

(0710[0-9]+)|(7109[0-9]+)|(109[0-9]*)|(071)|(710)

[samannoychatter]

Your code is giving error Warning: preg_match() [function.preg-match]: Unknown modifier '|'