C# Programming > Data

C# Random Array

Shuffle List

Unfortunately there is no automatic way to randomize, or shuffle, an array in C#. Yet all the pieces needed to mix a list randomly are already there. C#.Net comes with a built-in Random class, which may not be true random but works fine. C#.Net also comes with great support for strongly-typed array lists...

The C# Code

private List<string> MixList(List<string> inputList)
{
     List<string> randomList = new List<string>();
     if (inputList.Count == 0)
          return randomList;

     Random r = new Random();
     int randomIndex = 0;
     while (inputList.Count > 0)
     {
          randomIndex = r.Next(0, inputList.Count); //Choose a random object in the list
          randomList.Add(inputList[randomIndex]); //add it to the new, random list<
          inputList.RemoveAt(randomIndex); //remove to avoid duplicates
     }

     //clean up
     inputList.Clear();
     inputList = null;
     r = null;

     return randomList; //return the new random list
}

Some Thoughts

The C# function is written for a List<> of string types. To modify it to another data type or object, change all the List<string> occurances to List<[your type here]>.

As far as the logic of the function goes, it is quite simple. The C# function copies the original list into a new list, adding the elements in random order. The result is a randomized array list in C#.

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