Can I use javascript regular expression in php as it is - php

Question

I am using a regular expression in javascript and want to do server side validation as well with the same regular expression. Do i need to modify it to make it compatible or will it run as it is.
How to use PHP regular expresion. Please provide a small example.
Thanks in Advance
EDIT
For Email Validation
var pattern = new RegExp(/^(("[\w-\s]+")|([\w-]+(?:\.[\w-]+)*)|("[\w-\s]+")([\w-]+(?:\.[\w-]+)*))(#((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$)|(#\[?((25[0-5]\.|2[0-4][0-9]\.|1[0-9]{2}\.|[0-9]{1,2}\.))((25[0-5]|2[0-4][0-9]|1[0-9]{2}|[0-9]{1,2})\.){2}(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[0-9]{1,2})\]?$)/i);
For Phone no validation
var pattern = new RegExp(/^\(?(\d{3})\)?[- ]?(\d{3})[- ]?(\d{4})$/);

Answer 1

PHP regexp are based on PCRE (Perl Compatible Regular Expression).
Example (find digits) :
preg_match('/^[0-9]*$/', 'my01string');
See php documentation.
Javascript regexp are slightly different (ECMA).
var patt1 = new RegExp("e");
document.write(patt1.test("The best things in life are free"));
See here for a comparison table.

Answer 2

Supposed to work for most of the patterns, except escaping special characters and backslashes, but not reverse, php regex have features than javascript like look behind expressions.
javascript : /[a-z]+/
php : '/[a-z]+/'
For example,
var pattern = new RegExp(/^\(?(\d{3})\)?[- ]?(\d{3})[- ]?(\d{4})$/);
would be '/^\(?(\d{3})\)?[- ]?(\d{3})[- ]?(\d{4})$/' in php

Answer 3

You should use one of the following functions preg_match or preg_match_all. And with a bit of luck you shouldn't need to modify your regex.
PHP regex uses the classic Perl regex, so a match would look like
preg_match_all('/([a-zA-Z0-9]+)/', $myStringToBeTested, $results);
Later edit:
$string="test#mail.com";
if(preg_match('/^(("[\w-\s]+")|([\w-]+(?:\.[\w-]+)*)|("[\w-\s]+")([\w-]+(?:\.[\w-]+)*))(#((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$)|(#\[?((25[0-5]\.|2[0-4][0-9]\.|1[0-9]{2}\.|[0-9]{1,2}\.))((25[0-5]|2[0-4][0-9]|1[0-9]{2}|[0-9]{1,2})\.){2}(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[0-9]{1,2})\]?$)/', $string))
echo "matches!";
else
echo "doesn't match!";
Enjoy!

Answer 4

In PHP we use the function preg_match.
$email_pattern = '/^(("[\w-\s]+")|([\w-]+(?:\.[\w-]+)*)|("[\w-\s]+")([\w-]+(?:\.[\w-]+)*))(#((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$)|(#\[?((25[0-5]\.|2[0-4][0-9]\.|1[0-9]{2}\.|[0-9]{1,2}\.))((25[0-5]|2[0-4][0-9]|1[0-9]{2}|[0-9]{1,2})\.){2}(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[0-9]{1,2})\]?$)/i';
$phoneno_pattern = '^/\(?(\d{3})\)?[- ]?(\d{3})[- ]?(\d{4})$/';
if(preg_match($email_pattern,$input_email)) {
// valid email.
}
if(preg_match($phoneno_pattern,$input_ph)) {
// valid ph num.
}
You could have used the regex directly as the function argument instead of using a variable.