Shallow Vs Deep Copy

Hi,

1. Shallow copy is done by the object method MemberwiseClone()

2. DeepCopy requires the classes to be flagged as [Serializable]

Shallow Copy

1. Value type --> A bit-by-bit copy of the field is performed

2. Reference type --> The reference is copied but the referred object is not; therefore, the original object and its clone refer to the same object

Deep Copy

1. Value type --> A bit-by-bit copy of the field is performed

2. Reference type --> A new copy of the referred object is performed. Therefore, the original object and its clone refer to the seperate object

Code Snippet -

[Serializable] public class CopyObject { // Note: The classes to be cloned (Deep Copy) must be flagged as [Serializable]. Therefore the CopyObject must be declared as 'Serializable' public int Salary; public CopyObject(int salary) { this.Salary = salary; } }
public class ShallowCopy { public static string CompanyName = "My Company"; public int Age; public string EmployeeName; public CopyObject Salary; public ShallowCopy MakeShallowCopy(ShallowCopy inputcls) { return inputcls.MemberwiseClone() as ShallowCopy; } }	CopyObject clsref = new CopyObject(1000); ShallowCopy m1 = new ShallowCopy(); m1.Age = 25; m1.EmployeeName = "Ahmed Eid"; m1.Salary = new CopyObject(1000);; ShowHideError("Salary: " + m1.Salary.Salary.ToString(), true); // 1000 ShallowCopy m2 = m1.MakeShallowCopy(m1); m2.Salary.Salary = 2000; // Same Happens if you do it as - clsref.Salary = 2000; ShowHideError("Salary: " + m1.Salary.Salary.ToString(), true); // 2000
[Serializable] public class DeepCopy { public static string CompanyName = "My Company"; public int Age; public string EmployeeName; public CopyObject Salary; public static T MakeDeepCopy<T>(T item) { BinaryFormatter formatter = new BinaryFormatter(); MemoryStream stream = new MemoryStream(); formatter.Serialize(stream, item); stream.Seek(0, SeekOrigin.Begin); T result = (T)formatter.Deserialize(stream); stream.Close(); return result; } }	CopyObject clsref = new CopyObject(3000); DeepCopy m1 = new DeepCopy(); m1.Age = 25; m1.EmployeeName = "Ahmed Eid"; m1.Salary = clsref; ShowHideError("Salary: " + m1.Salary.Salary.ToString(), true); // 3000 DeepCopy m2 = DeepCopy.MakeDeepCopy<DeepCopy>(m1); m2.Salary.Salary = 4000; // Same Happens if you do it as - clsref.Salary = 2000; ShowHideError("Salary: " + m1.Salary.Salary.ToString(), true); // 3000

Hope this helps.

Thanks & Regards,

Arun Manglick || Senior Tech Lead