Editing Object copying (section)

{{Short description|Technique in object-oriented programming}}
In [[object-oriented programming]], '''object copying''' is [[object creation|creating]] a copy of an existing [[object (computer science)|object]], a unit of data in object-oriented programming. The resulting object is called an ''object copy'' or simply ''copy'' of the original object. Copying is basic but has subtleties and can have significant overhead. There are several ways to copy an object, most commonly by a [[copy constructor]] or [[cloning (programming)|cloning]]. Copying is done mostly so the copy can be modified or moved, or the current value preserved. If either of these is unneeded, a reference to the original data is sufficient and more efficient, as no copying occurs.

Objects in general store [[Composite data type|composite data]]. While in simple cases copying can be done by allocating a new, uninitialized object and copying all fields ([[attribute (computing)|attributes]]) from the original object, in more complex cases this does not result in desired behavior.