When to use ref and when it is not necessary in C#

by

Short answer: read my article on argument passing.

Long answer: when a reference type parameter is passed by value, only the reference is passed, not a copy of the object. This is like passing a pointer (by value) in C or C++. Changes to the value of the parameter itself won’t be seen by the caller, but changes in the object which the reference points to will be seen.

When a parameter (of any kind) is passed by reference, that means that any changes to the parameter are seen by the caller – changes to the parameter are changes to the variable.

The article explains all of this in more detail, of course 🙂

Useful answer: you almost never need to use ref/out. It’s basically a way of getting another return value, and should usually be avoided precisely because it means the method’s probably trying to do too much. That’s not always the case (TryParse etc are the canonical examples of reasonable use of out) but using ref/out should be a relative rarity.

More Related Contents:

  1. Why use the ‘ref’ keyword when passing an object?
  2. What’s the difference between the ‘ref’ and ‘out’ keywords?
  3. Assigning out/ref parameters in Moq
  4. Why is list when passed without ref to a function acting like passed with ref?
  5. How do I run this code
  6. Can’t use Count() in C#
  7. IOException: The process cannot access the file ‘file path’ because it is being used by another process
  8. A generic error occurred in GDI+, JPEG Image to MemoryStream
  9. How to get started with developing Internet Explorer extensions?
  10. How do I create a Dto in C# Asp.Net from a fairly complex Json Response
  11. How to convert a Decimal to a Double in C#?
  12. How can I get the client’s IP address in ASP.NET MVC?
  13. C# vs Java generics [duplicate]
  14. Why does the Contains() operator degrade Entity Framework’s performance so dramatically?
  15. How to return a specific status code and no contents from Controller?
  16. Passing just a type as a parameter in C#
  17. Using PropertyInfo to find out the property type
  18. How can I quickly up-cast object[,] into double[,]?
  19. HttpClient and using proxy – constantly getting 407
  20. Do the new C# 5.0 ‘async’ and ‘await’ keywords use multiple cores?
  21. request exceeds the configured maxQueryStringLength when using [Authorize]
  22. How to use TimeZoneInfo to get local time during Daylight Saving Time?
  23. Aspect Oriented Programming in C# [closed]
  24. Switch case on type c# [duplicate]
  25. downcast and upcast
  26. visual studio 2010 conditional references
  27. Timer run every 5th minute
  28. Closing Applications
  29. How to use Property Injection with AutoFac?
  30. How to send a mail using Microsoft.Office.Interop.Outlook.MailItem by specifying the From Address

Leave a Comment