|
clone() and the Cloneable Interface in Java
Java Interview Questions for Cloning and Cloneable
(Continued from previous question...)
clone() and the Cloneable Interface in Java
The clone( ) method generates a duplicate copy of the object on which it is called. Only classes that implement the Cloneable interface can be cloned.
The Cloneable interface defines no members. It is used to indicate that a class allows a bitwise copy of an object (that is, a clone) to be made.
If you try to call clone( ) on a class that does not implement Cloneable, a CloneNotSupportedException is thrown. When a clone is made, the constructor for the object being cloned is not called. A clone is simply an exact copy of the original.
Cloning is a potentially dangerous action, because it can cause unintended side effects.
For example, if the object being cloned contains a reference variable called obRef, then when the clone is made, obRef in the clone will refer to the same object as does obRef in the original. If the clone makes a change to the contents of the object referred to by obRef, then it will be changed for the original object, too.
(Continued on next question...)
Other Interview Questions
| 