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Object CloningCreating a copy of an object with fully replicated properties is not always the wanted behavior. A good example of the need for copy constructors, is if you have an object which represents a GTK window and the object holds the resource of this GTK window, when you create a duplicate you might want to create a new window with the same properties and have the new object hold the resource of the new window. Another example is if your object holds a reference to another object which it uses and when you replicate the parent object you want to create a new instance of this other object so that the replica has its own separate copy.
An object copy is created by using the $copy_of_object = clone $object; When an object is cloned, PHP will perform a shallow copy of all of the object's properties. Any properties that are references to other variables will remain references.
void __clone()
Once the cloning is complete, if a __clone() method is defined, then the newly created object's __clone() method will be called, to allow any necessary properties that need to be changed. Example #1 Cloning an object
The above example 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 ) ) It is possible to access a member of a freshly cloned object in a single expression: Example #2 Access member of freshly cloned object
The above example will output something similar to: 2016 |