devxlogo

Implementing IClonable – Shallow copies

Implementing IClonable – Shallow copies

An object that want to support cloning should implement the ICloneable interface. This interface exposes only one method, Clone, which returns a copy of the object. The ICloneable specifics don’t specify whether the object that the Clone method returns is a shallow copy or a deep copy. The difference is subtle, but important when the object being cloned has subobjects: a shallow copy creates a clone of the main (root) object, but doesn’t create a copy of any dependent object, whereas a deep copy would copy also all dependent objects.

For example, if you are cloning an array of ten Person objects, a shallow copy would create only one new object (the array), whereas a deep copy would create 11 new objects.

The simplest way to generate a shallow copy is to rely on the MemberwiseClone method that all objects inherit from System.Object. So in practice, you can use the same routine for all cloneable classes:

Class Person    Implements ICloneable    ' ...    Function Clone() As Object Implements ICloneable.Clone        Return Me.MemberwiseClone    End FunctionEnd Class

devx-admin

Share the Post: