C# | Gets or sets the element at the specified index in StringCollection

StringCollection.Item[Int32] Property is used to get or set the element at the specified index.

Syntax:

public string this[int index] { get; set; }

Here, index is the zero-based index of the entry to get or set.

Return Value: It returns the element of String type at the specified index.

Exception: This property throws ArgumentOutOfRangeException if the index is less than zero or index is equal to or greater than Count.

Below programs illustrate the use of above-discussed property:

Example 1:

// C# code to get or set the element at
// the specified index in StringCollection
using System;
using System.Collections;
using System.Collections.Specialized;

class GFG {

    // Driver code
    public static void Main()
    {

        // creating a StringCollection named myCol
        StringCollection myCol = new StringCollection();

        // Adding elements in StringCollection
        myCol.Add("A");
        myCol.Add("B");
        myCol.Add("C");
        myCol.Add("D");
        myCol.Add("E");

        // Displaying objects in myCol
        foreach(Object obj in myCol)
        {
            Console.WriteLine(obj);
        }

        Console.WriteLine("\nAfter Item[int32] Property: \n");

        // setting the value at index 2
        myCol[2] = "Z";

        // Displaying the elements
        // in the StringCollection
        foreach(Object obj1 in myCol)
        {
            Console.WriteLine(obj1);
        }
    }
}

Output:

A
B
C
D
E

After Item[int32] Property: 

A
B
Z
D
E

Example 2:

// C# code to get or set the element at
// the specified index in StringCollection
using System;
using System.Collections;
using System.Collections.Specialized;

class GFG {

    // Driver code
    public static void Main()
    {

        // creating a StringCollection named myCol
        StringCollection myCol = new StringCollection();

        // Adding elements in StringCollection
        myCol.Add("Geeks");
        myCol.Add("GFG");
        myCol.Add("DS");
        myCol.Add("Class");
        myCol.Add("Noida");

        // Displaying objects in myCol
        foreach(Object obj in myCol)
        {
            Console.WriteLine(obj);
        }

        Console.WriteLine("\nAfter Item[int32] Property: \n");

        // setting the value at index 8
        // this will give error as index
        // is greater than count
        myCol[8] = "C#";

        // Displaying the elements
        // in the StringCollection
        foreach(Object obj1 in myCol)
        {
            Console.WriteLine(obj1);
        }
    }
}

Runtime Error:

Unhandled Exception:
System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index

Reference:

• https://docs.microsoft.com/en-us/dotnet/api/system.collections.specialized.stringcollection.item?view=netframework-4.7.2