Use the BinarySearch() method to search charArray for 'o' : Array Search « Data Structure « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. Data Structure
3. Array Search

using System;

class MainClass
{

  public static void Main()
  {
    char[] charArray = {'w', 'e', 'l', 'c', 'o', 'm', 'e'};
    Array.Sort(charArray);  // sort the elements        
    int index = Array.BinarySearch(charArray, 'o');
    Console.WriteLine("Array.BinarySearch(charArray, 'o') = " + index);

  }

}

Array.BinarySearch(charArray, 'o') = 5