Matching a Valid Email Address
view source
print?
$email = '[email protected]'
 
if (!preg_match('#[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{1,10}#i', $email)) {
 
echo 'The email address you entered was invalid.';
 
}
Matching a string between 4 and 128 characters
view source
print?
$string = "tutorial";
 
if (!preg_match('#^(.){4,128}$#', $string)) {
 
echo 'The string you entered is invalid.';
 
}
Matching an integer between 1 and 16 characters in length
view source
print?
$int = 4;
 
if (!preg_match('#^[0-9]{1,16}$#', $int)) {
 
echo 'That is not a valid integer.';
 
}
Matching Content between any given HTML tag with attributes

simply replace �style� with HTML tag your trying to match.
view source
print?
$html = '<style class="sdfgsd">this is the matched pattern</style>';
 
preg_match('/<style(.*)?>(.*)?<\/style>/', $html, $match);
 
print $match[2];
Matching a Valid http:// URL
view source
print?
$url = http://www.tutorialcadet.com
 
if (!preg_match('/^(([\w]+:)?\/\/)?(([\d\w]|%[a-fA-f\d]{2,2})+(:([\d\w]|%[a-fA-f\d]{2,2})+)?@)?([\d\w][-\d\w]{0,253}[\d\w]\.)+[\w]{2,4}(:[\d]+)?(\/([-+_~.\d\w]|%[a-fA-f\d]{2,2})*)*(\?(&amp;?([-+_~.\d\w]|%[a-fA-f\d]{2,2})=?)*)?(#([-+_~.\d\w]|%[a-fA-f\d]{2,2})*)?$/', $url)) {
 
echo 'The URL you entered was invalid. Be sure to include <strong>http://</strong>';
 
}
Matching a US Phone Number
view source
print?
$phonenumber = '333-333-3333';
 
if(preg_match("/^[0-9]{3,3}[-]{1,1}[0-9]{3,3}[-]{1,1}[0-9]{4,4}$/", $phonenumber)) {
   echo $phonenumber;
 }
Matching a UK Phone Number
view source
print?
$ukphonenumber = '01614840484';
 
if(preg_match("/^[0-9]{11,11}$/", $ukphonenumber)) {
 
  echo $ukphonenumber;
 
}
Matching a UK Postal code
view source
print?
$postal = 'AL42PT';
 
if(preg_match("/^[A-Z]{1,2}([0-9]{1,2}|[0-9]{1,1}[A-Z]{1,1})( |)[0-9]{1,1}[A-Z]{2,2}$/", $postal)) {
 
  echo $postal;
 
}
Matching a US Zip Code
view source
print?
$zip = '55416';
 
if(preg_match("/^[0-9]{5,5}$/", $zip)) {
   echo $zip;
 }
Matching an IPv4 IP address
view source
print?
$ip = '233.122.122.255';
 
if(preg_match("/^(([1-9]?[0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]).){3}([1-9]?[0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$/", $ip)) {
 
  echo $ip;
 
}
Matching an IPv6 IP address
view source
print?
<?php
 
$ip = 'fe80:0000:0000:0000:0204:61ff:fe9d:f156';
 
if(preg_match("/^\s*((([0-9A-Fa-f]{1,4}:){7}([0-9A-Fa-f]{1,4}|:))|(([0-9A-Fa-f]{1,4}:){6}(:[0-9A-Fa-f]{1,4}|((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3})|:))|(([0-9A-Fa-f]{1,4}:){5}(((:[0-9A-Fa-f]{1,4}){1,2})|:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3})|:))|(([0-9A-Fa-f]{1,4}:){4}(((:[0-9A-Fa-f]{1,4}){1,3})|((:[0-9A-Fa-f]{1,4})?:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){3}(((:[0-9A-Fa-f]{1,4}){1,4})|((:[0-9A-Fa-f]{1,4}){0,2}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){2}(((:[0-9A-Fa-f]{1,4}){1,5})|((:[0-9A-Fa-f]{1,4}){0,3}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){1}(((:[0-9A-Fa-f]{1,4}){1,6})|((:[0-9A-Fa-f]{1,4}){0,4}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(:(((:[0-9A-Fa-f]{1,4}){1,7})|((:[0-9A-Fa-f]{1,4}){0,5}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:)))(%.+)?\s*$/", $ip)) {
   echo $ip;
 }
 
?>

http://www.tutorialcadet.com/10-useful-regex-patterns-for-php/

regular expression examples

regex

PHP