Deep Copy

Question

I am just learning about Deep Copy and I am a little confused. public Class Person { public string Position {get;set;} public Tools ToolData {get;set;} public GPS GpsData {get;set;} public Person DeepCopy() { Person copy = (Person) this .MemberwiseClone(); } } Does the above code truly create a deep copy of all the properties in the class or am I missing a step such as something like adding this to the code: copy.ToolData = this.ToolData; copy.GpsData = this.GpsData; I want to make sure that I an truly creating a new independent object from which it was copied from.

Vulpes · Answer

No the above code creates a shallow copy not a deep copy. The reason is that you have two (presumably mutable) reference type fields of types Tools and GPS. These fields contain reference to objects not the objects themselves. When you use MemberwiseClone it creates a copy of all the fields. In the case of the above two fields it copies the references - not the objects themselves. Consequently the clone will still refer to the same objects and won't therefore be truly independent. To create a deep clone you'd need methods to clone the Tools and GPS objects themselves.