What should I use an IEnumerable or IList? [duplicate]

Generally speaking, you should try and use the least specific type that suits your purpose. IEnumerable is less specific than IList (IList implements IEnumerable) so unless you want something specific from IList (such as Count as you suggest, or perhaps Add, Delete, etc), I’d use IEnumerable.

One benefit of remaining with IEnumerable is that you can write iterator methods to return this type (look up “yield return” and iterator methods if you are not familiar with them). This allows you to write very memory efficient “pipelines” for your loops.

Related Posts:

  1. Can anyone explain IEnumerable and IEnumerator to me? [closed]
  2. IEnumerable vs List – What to Use? How do they work?
  3. Converting from IEnumerable to List
  4. Convert from List into IEnumerable format
  5. How can I parse JSON with C#?
  6. What is IP address ‘::1’?
  7. What is the yield keyword used for in C#?
  8. Join/Where with LINQ and Lambda
  9. C# compiler error: “not all code paths return a value”
  10. C# equivalent of C++ map
  11. The page was not displayed because the request entity is too large on IIS
  12. Export Pervasive to MySQL (C#)
  13. Why use the params keyword?
  14. What does plus equals(+=) operator means here?
  15. The request was aborted: Could not create SSL/TLS secure channel
  16. finding the maximum length of lists in c#
  17. The located assembly’s manifest definition does not match the assembly reference
  18. LEFT OUTER JOIN in LINQ
  19. OnTriggerEnter not working at Unity3D
  20. The requested resource does not support HTTP method ‘GET’
  21. How can I find a specific element in a List?
  22. Rename a file in C#
  23. What does mscorlib stand for?
  24. What is the best way to iterate over a dictionary?
  25. What is and how to fix System.TypeInitializationException error?
  26. How to move 2D Object with WASD in Unity
  27. The Object you want to instantiate is null. Unity 3D
  28. Convert date yyyyMMdd to system.datetime format
  29. How to bind a model to a kendo Combobox in order to use the models validatation?
  30. HttpWebRequest-The remote server returned an error: (400) Bad Request
  31. MSHTML DLL on Windows 10
  32. Adding values to a C# array
  33. Adding values to a C# array
  34. What does {0} mean when found in a string in C#?
  35. How to use html.ValidationMessageFor
  36. EF 5 Enable-Migrations : No context type was found in the assembly
  37. What does the @ symbol before a variable name mean in C#?
  38. What is the C# version of VB.net’s InputDialog?
  39. Visual studio 2019 freezes when debugging
  40. How to make an HTTP POST web request
  41. How to add comments into a Xaml file in WPF?
  42. Are 2 dimensional Lists possible in c#?
  43. Passing just a type as a parameter in C#
  44. How to easily initialize a list of Tuples?
  45. How do I target @Model within a src of an image tag?
  46. How to stop C# console applications from closing automatically? [duplicate]
  47. Can I send SMS Messages from a C# Application?
  48. How do you sort a dictionary by value?
  49. EntityType has no key defined error
  50. regular expression “.*[^a-zA-Z0-9_].*”
  51. Sharing violation IOException while reading and writing to file C#
  52. How to delete object?
  53. WSACancelBlockingCall exception
  54. Carriage return and Line feed… Are both required in C#?
  55. Padding is invalid and cannot be removed?
  56. Inconsistent Accessibility: Parameter type is less accessible than method
  57. Why is it that “No HTTP resource was found that matches the request URI” here?
  58. How to get correct timestamp in C#
  59. Cannot implicitly convert type ‘int’ to ‘string’ C# class
  60. If a folder does not exist, create it
  61. C# “No suitable method found to override.” — but there is one
  62. System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
  63. What is the purpose of global.asax in asp.net
  64. How to add a string to a string[] array? There’s no .Add function
  65. How to block until an event is fired in c#
  66. How to use WPF Background Worker
  67. Case insensitive ‘Contains(string)’
  68. How to catch all exceptions in c# using try and catch?
  69. Getting “Handshake failed…unexpected packet format” when using WebClient.UploadFile() with “https” when the server has a valid SSL certificate
  70. Most efficient way to remove special characters from string
  71. Receiving access denied error from Visual Studio when trying to change target framework
  72. How to force garbage collector to run?
  73. Page vs Window in WPF?
  74. CS1617: Invalid option ‘6’ for /langversion; must be ISO-1, ISO-2, 3, 4, 5 or Default
  75. Sort list by field (C#)
  76. How to post data to specific URL using WebClient in C#
  77. Value does not fall within the expected range
  78. The type or namespace name could not be found
  79. How to execute a stored procedure within C# program
  80. The remote server returned an error: (405) Method Not Allowed. WCF REST Service
  81. TTS Voices for Windows7 64 bits
  82. How can I delete a file that is in use by another process?
  83. How to crop an image using C#?
  84. Convert double to float by cast or Convert.ToSingle()?
  85. Call a stored procedure with parameter in c#
  86. Type Checking: typeof, GetType, or is?
  87. How do you wait for input on the same Console.WriteLine() line?
  88. C# Macro definitions in Preprocessor
  89. Adding images to buttons from Imagelist on a toolstrip?
  90. Multiple cases in switch statement
  91. System.ArgumentNullException: Value cannot be null. Parameter name: source
  92. Sequence contains more than one element
  93. Drawing circles with System.Drawing
  94. Parser Error Message: Could not load type ‘sometype’
  95. Get local IP address
  96. Delay function in C#
  97. Cannot declare instance members in a static class in C#
  98. Error: “an object reference is required for the non-static field, method or property…” [duplicate]
  99. How to convert HTML to PDF using iTextSharp
  100. Linq: GroupBy, Sum and Count

Leave a Comment