/**
* Extract the last `$num` characters from a string.
*
* @param string $str
* the string to extract the characters from.
* @param integer $num
* the number of characters to extract.
* @return string|boolean
* a string containing the last `$num` characters of the
* input string, or false on failure.
*/
public static function right($str, $num){
$str = substr($str, strlen($str)-$num, $num);
return $str;
}
/**
* Extract the first `$num` characters from a string.
*
* @param string $str
* the string to extract the characters from.
* @param integer $num
* the number of characters to extract.
* @return string|boolean
* a string containing the last `$num` characters of the
* input string, or false on failure.
*/
public static function left($str, $num){
$str = substr($str, 0, $num);
return $str;
}