Index of first occurrence in StringCollection in C#?

To get the index of first occurrence in StringCollection, the code is as follows −

Example

 Live Demo

using System;
using System.Collections.Specialized;
public class Demo {
   public static void Main() {
      StringCollection strCol = new StringCollection();
      strCol.Add("Accessories");
      strCol.Add("Books");
      strCol.Add("Electronics");
      strCol.Add("Books");
      Console.WriteLine("StringCollection elements...");
      foreach (string res in strCol) {
         Console.WriteLine(res);
      }
      strCol.Insert(2, "Headphone");
      Console.WriteLine("StringCollection elements...UPDATED");
      foreach (string res in strCol) {
         Console.WriteLine(res);
      }
      Console.WriteLine("Index of first occurrence of Books? = "+strCol.IndexOf("Books"));
   }
}

Output

This will produce the following output −

StringCollection elements...
Accessories
Books
Electronics
Books
StringCollection elements...UPDATED
Accessories
Books
Headphone
Electronics
Books
Index of first occurrence of Books? = 1

Example

Let us now see another example −

 Li ve Demo

using System;
using System.Collections.Specialized;
public class Demo {
   public static void Main() {
      StringCollection strCol = new StringCollection();
      String[] strArr = new String[] { "A", "B", "C", "D", "E", "F", "D", "H" };
      Console.WriteLine("StringCollection elements...");
      foreach (string str in strArr) {
         Console.WriteLine(str);
      }
      strCol.AddRange(strArr);
      Console.WriteLine("Element at 5th index = "+strCol[5]);
      Console.WriteLine("Count of strings in StringCollection = " + strCol.Count);
      Console.WriteLine("Index of first occurrence of D? = "+strCol.IndexOf("D"));
   }
}

Output

This will produce the following output −

StringCollection elements...
A
B
C
D
E
F
D
H
Element at 5th index = F
Count of strings in StringCollection = 8
Index of first occurrence of D? = 3