PHP advanced object construction and the use of multiple constructors_PHP tutorial

class classUtil {//This is a parameter processing Class
public static function typeof($var){
if (is_object($var)) return get_class($var);//If it is an object, get the class name
if (is_array($var) ) return "array";//If it is an array, return "array"
if (is_numeric($var)) return "numeric";//If it is a number, return "numeric"
return "string"; //String return "string"
}
public static function typelist($args){
return array_map(array("self","typeof"),$args);//Array loop through Call self::typeof to process each element in $args
}
public static function callMethodForArgs($object,$args,$name="construct"){
$method=$name."_ ".implode("_",self::typelist($args));//implode is to use "_" to connect the array elements into a string
if (!is_callable(array($object,$method) )){//is_callable() function tests whether $object::$method is a callable structure
echo sprintf("Class %s has no methd '$name' that takes".
"arguments (% s)",get_class($object),implode(",",self::typelist($args)));
call_user_func_array(array($object,$method),$args);//call_user_func_array function call $object::$method($args)
}
}
}
class dateAndTime {
private $timetamp;
public function __construct(){//own constructor
$args=func_get_args();//Get parameters
classUtil::callMethodForArgs($this,$args);//Call the method of parameter processing class
}
public function construct_(){ //When the parameter is empty
$this->timetamp=time();
}
public function construct_dateAndTime($datetime){//When it is the class itself
$this-> ;timetamp=$datetime->getTimetamp();
}
public function construct_number($timestamp){//When it is a number
$this->timetamp=$timestamp;
}
public function construct_string($string){//When it is a time string
$this->timetamp=strtotime($string);
}
public function getTimetamp(){// Method to obtain timestamp
return $this->timetamp;
}
}
?>