How to get the Index of Specified Element in a List in C# - Step by Step Examples

How to get the Index of Specified Element in a List in C# ?

Answer

To find the index of a specified element in a list in C#, you can use the IndexOf method of the List class.


✐ Examples

1 Find Index of Element in List (Integer)

In this example,

  1. We create a list named myList with some elements.
  2. We use the IndexOf method to find the index of the specified element in the list.
  3. The IndexOf method returns the index of the first occurrence of the element in the list, or -1 if the element is not found.
  4. Finally, we print the index to standard output.

C# Program

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        List<int> myList = new List<int> { 10, 20, 30, 40, 50 };
        int searchElement = 40;
        int index = myList.IndexOf(searchElement);
        if (index != -1)
        {
            Console.WriteLine("Index of element is: " + index);
        }
        else
        {
            Console.WriteLine("Element not found");
        }
    }
}

Output

Index of element is: 3

2 Find Index of Element in List (String)

In this example,

  1. We create a list named myList with some string elements.
  2. We use the IndexOf method to find the index of the specified string in the list.
  3. The IndexOf method returns the index of the first occurrence of the string in the list, or -1 if the string is not found.
  4. Finally, we print the index to standard output.

C# Program

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        List<string> myList = new List<string> { "apple", "banana", "cherry", "date", "elderberry" };
        string searchElement = "cherry";
        int index = myList.IndexOf(searchElement);
        if (index != -1)
        {
            Console.WriteLine("Index of element is: " + index);
        }
        else
        {
            Console.WriteLine("Element not found");
        }
    }
}

Output

Index of element is: 2

Summary

In this tutorial, we learned How to get the Index of Specified Element in a List in C# language with well detailed examples.


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