Deleting A Specified Element In An Array Using Random Class

Question

class Check
{
     public static void Main()
     {         
              int[] arr1 = new int[] { 1, 2, 3 };
              Console.WriteLine(\"The Number That Left Us          


        

Answer 1

Arrays can't be dynamically resized in .NET, so you can't really 'remove' an item from an array (you could set it to 0, but I don't think that's what you want).

Try using a List<int> instead:

List<int> list = new List<int>() { 1, 2, 3 };
Console.WriteLine("The Number That Left Us Is");
Random rnd = new Random();
int r = rnd.Next(list.Count);
int Left = (list[r]);
list.Remove(Left);
Console.WriteLine(Left);

Answer 2

Arrays can not be re-sized, one you set them they are that size forever.

The "best" option is use a List<int> instead of an int[]

class Check
{
     public static void Main()
     {         
              List<int> arr1 = List<int>int[] { 1, 2, 3 };
              Console.WriteLine("The Number That Left Us Is");
              Random rnd = new Random();
              int r = rnd.Next(arr1.Length);
              int Left = (arr1[r]);
              arr1.RemoveAt(r);
              Console.WriteLine(Left);
      }
 }

To actually create a new array of one size smaller will take more code.

class Check
{
     public static void Main()
     {         
              int[] arr1 = int[] { 1, 2, 3 };
              Console.WriteLine("The Number That Left Us Is");
              Random rnd = new Random();
              int r = rnd.Next(arr1.Length);
              int Left = (arr1[r]);

              int oldLength = arr1.Length;
              arrTmp = arr1;                  
              arr1 = new int[oldLength - 1];
              Array.Copy(arrTmp, arr1, r);
              Array.Copy(arrTmp, r+1, arr1, r, oldLength - r - 1);

              Console.WriteLine(Left);
      }
 }

---

You mention "You gotta stick with the arrays", it is VERY easy to turn the list in to an array

class Check
{
     public static void Main()
     {         
              List<int> arr1 = List<int>int[] { 1, 2, 3 };
              Console.WriteLine("The Number That Left Us Is");
              Random rnd = new Random();
              int r = rnd.Next(arr1.Length);
              int Left = (arr1[r]);
              arr1.RemoveAt(r);
              Console.WriteLine(Left);
              SomeFunctionThatTakesAnArrayAsAnArgument(arr1.ToArray());
      }
 }

Answer 3

Arrays cannot be resized, if you want to remove items use a List<T>.

However, you can create a new one. If you want to keep all items but one at the random index:

arr1 = arr1.Where((i, index) => index != r).ToArray();

With a list you can use RemoveAt which is more efficient than creating arrays:

var list = new List<int> { 1, 2, 3 };
list.RemoveAt(r);

Answer 4

Try to following it removes the item from the list and creates a new array without the specific item.

static void Main(string[] args)
{
       int[] arr1 = new int[] { 1, 2, 3 };
      Console.WriteLine("The Number That Left Us Is");
      Random rnd = new Random();
      int r = rnd.Next(arr1.Length);

      // Create a new array except the item in the specific location
      arr1 = arr1.Except(new int[]{arr1[r]}).ToArray();
      int Left = (arr1[r]);
      Console.WriteLine(Left);
}