Preg_Match Regular Expression Samples

This PHP function is usually use in searching a string. It compares the two strings (search_pattern and string_given) and return 0 or 1 value. 1 denotes successful return while 0 is failure.

Preg_Match Parameter

preg_match(search_patter, $string_given)

search_pattern – string which formatted in regular expression.
$string_given - a given string that you’re comparing to.

When to use Preg_match function?

Preg_match is usually used for search string functionality, string validation, manipulation of text. The most common use of preg_match is in validating email, phone number, name etc….
Here are some basic regular expression in using preg_macth function.

Important Notes Before you begin.

1. Preg_macth is case sensitive so better to user strtolower function in your $string given parameter.
2. Observe "/ /" format. Regular expressions are formed by starting with a forward slash /, followed by a sequence of special symbols and words to match, then another slash and, optionally, a string of letters that affect the expression.

BASIC

<?php
    if (preg_match("/test/", "test")) {
        echo "Got match!\n";
    }

    if (preg_match("/php/i", "php")) {
        echo "Got match!\n";
    }
   
?>

EMAIL

<?php

if (preg_match('/^[^@]+@[a-zA-Z0-9._-]+\.[a-zA-Z]+$/', $email)){
 echo "Email is valid!\n";
}

?>

DOMAIN

<?php

preg_match('@^(?:http://)?([^/]+)@i', "http://www.webdosh.net/index.html", $match);
$hostname = $match[1];

// get last two segments of host name
preg_match('/[^.]+\.[^.]+$/', $hostname, $match);
echo "domain name is: {$match[0]}\n";

?>

PHONE

<?php
if(! preg_match('/^\d{2}(-\d{3}){2}(\d{2})?$/', $phone)) {
echo "<p> Error message</p>";
}
?>

to see more examples visit php.net