C# | ArrayList.InsertRange() Method

ArrayList.InsertRange(Int32, ICollection) Method in C# is used to insert the elements from a collection into the ArrayList at a specified index. That is the inserted element belongs to a collection(i.e. queue etc).

Syntax:

public virtual void InsertRange (int index, ICollection element);

Parameters:

• index: It is the index, where the new elements to be inserted.
• element: It is the ICollection whose elements are going to be inserted into the ArrayList at a specified index.

Note: The collection cannot be null, but it can contain elements that are null.

Exceptions:

• ArgumentNullException: If the element is null.
• ArgumentOutOfRangeException: If the index is less than zero or index is greater than counter.
• NotSupportedException: If the ArrayList is read-only or the ArrayList has a fixed size.

Example 1:

// C# program to demonstrate the
// ArrayList.InsertRange(Int32,
// ICollection) Method
using System;
using System.Collections;

class GFG {

    // Main Method
    public static void Main()
    {
        // initializes a new ArrayList
        ArrayList ArrList = new ArrayList();

        // adding values in the
        // ArrayList using "Add"
        ArrList.Add("A");
        ArrList.Add("D");
        ArrList.Add("E");
        ArrList.Add("F");

        // initializes a new Stack
        // as collection
        Stack s = new Stack();

        // pushing values in the stack
        // values are pop as B, C
        s.Push("C");
        s.Push("B");

        // Displays the ArrayList and the Queue
        Console.WriteLine("The ArrayList initially has:");
        Display(ArrList);
        Console.WriteLine("The collection initially has:");
        Display(s);

        // Copies the elements of the stack
        // to the ArrayList at index 1.
        ArrList.InsertRange(1, s);

        // Displays the ArrayList.
        Console.WriteLine("After insert the collection in the ArrList:");
        Display(ArrList);
    }

    // Display function
    public static void Display(IEnumerable ArrList)
    {
        foreach(Object a in ArrList)
        {
            Console.Write("   " + a);
        }
        Console.WriteLine();
    }
}

Output:

The ArrayList initially has:
   A   D   E   F
The collection initially has:
   B   C
After insert the collection in the ArrList:
   A   B   C   D   E   F

Example 2:+

// C# program to demonstrate the
// ArrayList.InsertRange(Int32,
// ICollection) Method
using System;
using System.Collections;

class GFG {

    // Main Method
    public static void Main()
    {
        // initializes a new ArrayList
        ArrayList ArrList = new ArrayList();

        // adding values in the ArrayList
        // using "Insert" method
        ArrList.Insert(0, "A");
        ArrList.Insert(1, "D");
        ArrList.Insert(2, "E");
        ArrList.Insert(3, "G");

        // Initializes a new Stack
        // as collection
        Stack s = new Stack();

        // pushing values in the stack
        // values are pop as B, C
        s.Push("C");
        s.Push("B");

        // Displays the ArrayList and the Queue.
        Console.WriteLine("The ArrayList initially has:");
        Display(ArrList);
        Console.WriteLine("The collection initially has:");
        Display(s);

        // Copies the elements of the stack
        // to the ArrayList at index 1.
        ArrList.InsertRange(1, s);

        // Displays the ArrayList.
        Console.WriteLine("After insert the collection in the ArrList:");
        Display(ArrList);

        // insert F by finding the index of G
        // using IndexOf() method
        ArrList.Insert(ArrList.IndexOf("G"), "F");
        Console.WriteLine("After inserting F before G:");
        Display(ArrList);
    }

    // Display function
    public static void Display(IEnumerable ArrList)
    {
        foreach(Object a in ArrList)
        {
            Console.Write(" " + a);
        }
        Console.WriteLine();
    }
}

Output:

The ArrayList initially has:
 A D E G
The collection initially has:
 B C
After insert the collection in the ArrList:
 A B C D E G
After inserting F before G:
 A B C D E F G

Reference:

• https://docs.microsoft.com/en-us/dotnet/api/system.collections.arraylist.insertrange?view=netframework-4.8