Validate domain name or check if a string contains a domain name using PHP

check-if-contain-domain-name.php

<?php

/**
 * Checks if string contains a domain name
 * @param $string
 * @return false|int
 */
function checkIfContainsDomainName($string)
{
    $pattern = '/(http[s]?\:\/\/)?(?!\-)(?:[a-zA-Z\d\-]{0,62}[a-zA-Z\d]\.){1,126}(?!\d+)[a-zA-Z\d]{1,63}/';
    return preg_match($pattern, $string);
}

?>

validate-domain-name.php

<?php

/**
 * Validates domain name
 * @param $domain
 * @return false|int
 */
function validateDomainName($domain)
{
    $pattern = '/^(http[s]?\:\/\/)?(?!\-)(?:[a-zA-Z\d\-]{0,62}[a-zA-Z\d]\.){1,126}(?!\d+)[a-zA-Z\d]{1,63}$/';
    return preg_match($pattern, $domain);
}

?>