PHP Object replication

In most cases, we do not need to completely copy an object to get its properties. But there is one case where it really needs to be: If you have a GTK window object, the object holds the window-related resources. You may want to copy a new window, keeping all properties the same as the original window, but it must be a new object (because if it is not a new object, the change in one window will affect the other window). Another case: If object A holds a reference to object B, when you copy object A, the object you want to use is no longer an object B but a copy of B, then you must get a copy of object A. Object replication can be done by using the Clone keyword (which, if possible, calls the object's __clone () method). The __clone () method in the object cannot be called directly.

$copy _of_object = Clone $object;

When the object is copied, PHP 5 performs a shallow copy of all the properties of the object (shallow copy). All reference properties will still be a reference to the original variable.

void __clone (void)

When the copy is complete, if the __clone () method is defined, the __clone () method in the newly created object (copy generated object) is called and can be used to modify the value of the property, if necessary.

Copy an Object

<?php    class subobject    {        static $instances = 0;        public $instance;        Public Function __construct () {            $this->instance = ++self:: $instances;        }        Public Function __clone () {            $this->instance = ++self:: $instances;        }    }    Class mycloneable    {public        $object 1;        Public $object 2;        function __clone ()        {            //forces a copy of This->object, otherwise it still points to the same object            $this->object1 = Clone $this Object1;        }    }    $obj = new mycloneable ();    $obj->object1 = new Subobject ();    $obj->object2 = new Subobject ();    $obj 2 = clone $obj;    Print ("Original object:\n");    Print_r ($obj);    Print ("Cloned object:\n");    Print_r ($obj 2);? >

The above routines will output:

Original object:mycloneable Object (    [Object1] = subobject object        (            [instance] = 1        )    [ OBJECT2] = subobject object        (            [instance] = 2        )) Cloned object:mycloneable object (    [Object1] = > Subobject Object        (            [Instance] = 3        )    [Object2] = subobject object        (            [ Instance] = 2        ))

