PHP/Reflection/is a

Determining Whether An Object Is An Instance Of A Particular Class

 
<?
class Shape { 
    function __construct() 
    { 
    } 
} 

$polly = new Shape("Polynesia"); 
print is_a($polly, "Shape") ? "" : "not "; 
?>

PHP is_ Functions

 
Data Type       Return Type         Function 
Boolean         bool                is_bool ( mixed var ) 
Integer         bool                is_int ( mixed var ) 
Double          bool                is_float ( mixed var ) 
String          bool                is_string ( mixed var ) 
Array           bool                is_array ( mixed var ) 
Object          bool                is_object ( mixed var ) 
Resource        bool                is_resource ( mixed var ) 
NULL            bool                is_null ( mixed var )