solution
PHP string processing functions class
One of the most common things any programmer will have to do is work with strings. Whether it be validating, checking value or sanitizing. Something I find helpful is to wrap functionality in classes so I can easily reuse them later. Here are a few string functions that I’ve found helpful. Don’t hesitate to comment with string functions you’ve found helpful!
class string
{
/**
* Checks to see if string is only alphabetic
*
* @param string $value
* @param boolean $ignore_spaces
* @return boolean
*/
static function isAlpha($value, $ignore_spaces = false)
{
if (!isset($value))
{
return false;
}
if ($ignore_spaces)
{
$value = str_replace(" ", "", $value);
}
return ctype_alpha($value);
}
/**
* Checks to see if string only contains letters and numbers
*
* @param string $value
* @param boolean $ignore_spaces
* @return boolean
*/
static function isAlphaNum($value, $ignore_spaces = false)
{
if (!isset($value))
{
return false;
}
if ($ignore_spaces)
{
$value = str_replace(" ", "", $value);
}
return ctype_alnum($value);
}
/**
* Checks to see if a string is numeric
*
* @param string $value
* @param boolean $ignore_spaces
* @return boolean
*/
static function isNumeric($value, $ignore_spaces = false)
{
if (!isset($value))
{
return false;
}
if ($ignore_spaces)
{
$value = str_replace(" ", "", $value);
}
return ctype_digit($value);
}
/**
* Checks to see if string is a valid phone number
*
* @param string $value
* @return boolean
*/
static function isPhone($value)
{
if (!isset($value))
{
return false;
}
if(ereg("^[0-9]{3}-[0-9]{3}-[0-9]{4}$", $value) ||
ereg("^\([0-9]{3}\)-[0-9]{3}-[0-9]{4}$", $value) ||
ereg("^\([0-9]{3}\)[0-9]{3}-[0-9]{4}$", $value) ||
ereg("^\([0-9]{3}\) [0-9]{3}-[0-9]{4}$", $value) ||
ereg("^[0-9]{3}[0-9]{3}[0-9]{4}$", $value) ||
ereg("^[0-9]{3} [0-9]{3} [0-9]{4}$", $value)
)
{
return true;
}
else
{
return false;
}
}
/**
* Checks to see if a string is an email
*
* @param string $value
* @param boolean $check_domain
* @return boolean
*/
public static function isEmail($value, $check_domain = false)
{
if (!isset($value))
{
return false;
}
if(eregi("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$", $value))
{
if ($check_domain == true)
{
list($userName, $mailDomain) = split("@", $value);
if (checkdnsrr($mailDomain, "MX")) {
return true;
}
else
{
return false;
}
}
return true;
}
else
{
return false;
}
}
/**
* Checks to see if a string is a valid zip code
*
* @param string $value
* @param boolean $extended
* @return boolean
*/
static function isZip($value, $extended = false)
{
if (!isset($value))
{
return false;
}
if (!$extended)
{
if(ereg("^[0-9]{5}$", $value))
{
return true;
}
else
{
return false;
}
}
else
{
if(ereg("^[0-9]{5}$", $value) || ereg("^[0-9]{5}-[0-9]{4}$", $value))
{
return true;
}
else
{
return false;
}
}
}
/**
* Validates credit card number
*
* @param string $value
* @return boolean
*/
static function isCreditCard($value)
{
if (!isset($value))
{
return false;
}
if (ereg("(^(4|5)\d{3}-?\d{4}-?\d{4}-?\d{4}|(4|5)\d{15})|(^(6011)-?\d{4}-?\d{4}-?\d{4}|(6011)-?\d{12})|(^((3\d{3}))-\d{6}-\d{5}|^((3\d{14})))", $value))
{
return true;
}
else
{
return false;
}
}
/**
* Strips html out of a string
*
* @param string $value
*/
static function stripHTML(&$value)
{
if (!isset($value))
{
exit;
}
$breaks[] = "<br>";
$breaks[] = "<br />";
$search = array('@<script[^>]*?>.*?</script>@si', // Strip out javascript
'@<style[^>]*?>.*?</style>@siU' // Strip style tags properly
);
$value = preg_replace($search, '', $value);
$value = str_ireplace($breaks, "\r\n", $value);
$value = trim($value);
$value = strip_tags($value);
$value = html_entity_decode($value, ENT_QUOTES);
$value = addslashes($value);
}
static function cleanHTML(&$value)
{
$search = array('@<script[^>]*?>.*?</script>@si', // Strip out javascript
'@<style[^>]*?>.*?</style>@siU' // Strip style tags properly
);
$value = preg_replace($search, '', $value);
$value = htmlentities($value);
}
}
