PHP | Type Casting and Conversion of an Object to an Object of other class
Given a PHP class object and the task is to convert or cast this object into object of another class.
Approach 1: Objects which are instances of a standard pre-defined class can be converted into object of another standard class.
Example:
<?php // PHP program to show // standard type casting   $a = 1; var_dump($a);   // int to float $a = (float) $a; var_dump($a);   // float to double $a = (double) $a; var_dump($a);   // double to real $a = (real) $a; var_dump($a);   // real to int $a = (int) $a; var_dump($a);   // int to integer $a = (integer) $a; var_dump($a);   // integer to bool $a = (bool) $a; var_dump($a);   // bool to boolean $a = (boolean) $a; var_dump($a);   // boolean to string $a = (string) $a; var_dump($a);   // string to array $a = (array) $a; var_dump($a);   // array to object $a = (object) $a; var_dump($a);   // object to unset/NULL $a = (unset) $a; var_dump($a);   ?> |
int(1)
float(1)
float(1)
float(1)
int(1)
int(1)
bool(true)
bool(true)
string(1) "1"
array(1) {
[0]=>
string(1) "1"
}
object(stdClass)#1 (1) {
[0]=>
string(1) "1"
}
NULL
Approach 2: Create a constructor for final class and add a foreach loop for assignment of all properties of initial class to instance of final class.
Example:
<?php // PHP program to convert an class object // to object of another class   // Original class class Geeks1 {           var $a = 'zambiatek';           function print_zambiatek() {         print('zambiatek');     } }   // Final class class Geeks2 {       // Constructor function of class Geeks2     public function __construct($object) {           // Initializing class properties         foreach($object as $property => $value) {             $this->$property = $value;         }     } }   // Initializing an object of class Geeks1 $object1 = new Geeks1();   // Printing original object of class Geeks1 print_r($object1);   // Initializing an object of class Geeks2 // using an object of class Geeks1 $object1 = new Geeks2($object1);   // Printing object of class Geeks2 print_r($object1);   ?> |
Geeks1 Object
(
[a] => zambiatek
)
Geeks2 Object
(
[a] => zambiatek
)
Approach 3: Write a function to convert object of the initial class into serialized data using serialize() method. Unserialize this serialized data into instance of the final class using unserialize() method.
Note: Member functions cannot be transferred using this approach. This approach can only be used if initial class contains only variables as members.
Example:
<?php // PHP program to convert an class object // to object of another class   // Original class class Geeks1 {           var $a = 'zambiatek';           function print_zambiatek() {         print('zambiatek');     } }   // Final class class Geeks2 {           /* Empty abstract class */}   // Function to convert class of given object function convertObjectClass($object, $final_class) {     return unserialize(sprintf(         'O:%d:"%s"%s',         strlen($final_class),         $final_class,         strstr(strstr(serialize($object), '"'), ':')     )); }   // Initializing an object of class Geeks2 $object1 = new Geeks1();   // Printing original object of class Geeks1 print_r($object1);   // Converting an object of class Geeks1 // into an object of class Geeks2 $object1 = convertObjectClass($object1, 'Geeks2');   // Printing object of class Geeks2 print_r($object1);   ?> |
Geeks1 Object
(
[a] => zambiatek
)
Geeks2 Object
(
[a] => zambiatek
)
Note: In general, PHP doesn’t allow type casting of user defined classes, while conversion/casting can be achieved indirectly by approaches presented above.
