what are the methods “public override bool equals(object obj)” and “public override int gethashcode()” doing? [closed]

by

Most types in .NET derive from the type System.Object, simply called object in C#. (E.g. interfaces don’t, however their implementations do.)

System.Object declares the methods Equals and GetHashCode as well as other members. (Note: The case matters in C#). The types you create automatically inherit these methods.

The task of Equals is to compare an object to another. The default implementation for reference types is to compare the references. If you want to change this behavior, you will have to override this method.

GetHashCode calculates the hash code of an object and is used in hash tables. For instance the types Dictionary<TKey,TValue> and HashSet<T> make use of it.
See Hashtable and Dictionary Collection Types. If you override Equals, you have to override GetHashCode as well in order to keep consistency.

More Related Contents:

  1. Overriding GetHashCode for mutable objects?
  2. Why is it important to override GetHashCode when Equals method is overridden?
  3. Difference between new and override
  4. What’s a “static method” in C#?
  5. C# – Keyword usage virtual+override vs. new
  6. Reflection: How to Invoke Method with parameters
  7. Overriding vs method hiding [duplicate]
  8. new keyword in method signature
  9. Detect if a method was overridden using Reflection (C#)
  10. Is it possible to override a non-virtual method?
  11. .NET unique object identifier
  12. C# optional parameters on overridden methods
  13. Why / when would it be appropriate to override ToString?
  14. How to make method call another one in classes?
  15. How to check whether an object has certain method/property?
  16. How to receive Plug & Play device notifications without a windows form
  17. Passing just a type as a parameter in C#
  18. C# Generic Operators
  19. How do I overload the [] operator in C# [duplicate]
  20. Does String.GetHashCode consider the full string or only part of it?
  21. C#: How to create an attribute on a method triggering an event when it is invoked?
  22. explicit conversion operator error when converting generic lists
  23. Operator overloading ==, !=, Equals
  24. Method vs Property in C# – what’s the difference [duplicate]
  25. How to call custom operator with Reflection
  26. Why must C# operator overloads be static?
  27. GetHashCode() gives different results on different servers?
  28. Why are there no lifted short-circuiting operators on `bool?`?
  29. Method to get all files within folder and subfolders that will return a list
  30. Generate List of methods of a class with method types

Leave a Comment