List<T>.InsertRange(Int32, IEnumerable<T>) Method

Reference

Definition

Namespace:: System.Collections.Generic

Assembly:: System.Collections.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Source:: List.cs

Source:: List.cs

Source:: List.cs

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Inserts the elements of a collection into the List<T> at the specified index.

public:
 void InsertRange(int index, System::Collections::Generic::IEnumerable<T> ^ collection);

public void InsertRange (int index, System.Collections.Generic.IEnumerable<T> collection);

member this.InsertRange : int * seq<'T> -> unit

Public Sub InsertRange (index As Integer, collection As IEnumerable(Of T))

Parameters

index: Int32

The zero-based index at which the new elements should be inserted.

collection: IEnumerable<T>

The collection whose elements should be inserted into the List<T>. The collection itself cannot be null, but it can contain elements that are null, if type T is a reference type.

Exceptions

ArgumentNullException

collection is null.

ArgumentOutOfRangeException

index is less than 0.

-or-

index is greater than Count.

Examples

The following example demonstrates InsertRange method and various other methods of the List<T> class that act on ranges. After the list has been created and populated with the names of several peaceful plant-eating dinosaurs, the InsertRange method is used to insert an array of three ferocious meat-eating dinosaurs into the list, beginning at index location 3.

using namespace System;
using namespace System::Collections::Generic;

void main()
{
    array<String^>^ input = { "Brachiosaurus", 
                              "Amargasaurus", 
                              "Mamenchisaurus" };

    List<String^>^ dinosaurs = 
        gcnew List<String^>((IEnumerable<String^>^) input);

    Console::WriteLine("\nCapacity: {0}", dinosaurs->Capacity);

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs )
    {
        Console::WriteLine(dinosaur);
    }

    Console::WriteLine("\nAddRange(dinosaurs)");
    dinosaurs->AddRange(dinosaurs);

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs )
    {
        Console::WriteLine(dinosaur);
    }

    Console::WriteLine("\nRemoveRange(2, 2)");
    dinosaurs->RemoveRange(2, 2);

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs )
    {
        Console::WriteLine(dinosaur);
    }

    input = gcnew array<String^> { "Tyrannosaurus", 
                                   "Deinonychus", 
                                   "Velociraptor"};

    Console::WriteLine("\nInsertRange(3, (IEnumerable<String^>^) input)");
    dinosaurs->InsertRange(3, (IEnumerable<String^>^) input);

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs )
    {
        Console::WriteLine(dinosaur);
    }

    Console::WriteLine("\noutput = dinosaurs->GetRange(2, 3)->ToArray()");
    array<String^>^ output = dinosaurs->GetRange(2, 3)->ToArray();
        
    Console::WriteLine();
    for each(String^ dinosaur in output )
    {
        Console::WriteLine(dinosaur);
    }
}

/* This code example produces the following output:

Capacity: 3

Brachiosaurus
Amargasaurus
Mamenchisaurus

AddRange(dinosaurs)

Brachiosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Amargasaurus
Mamenchisaurus

RemoveRange(2, 2)

Brachiosaurus
Amargasaurus
Amargasaurus
Mamenchisaurus

InsertRange(3, (IEnumerable<String^>^) input)

Brachiosaurus
Amargasaurus
Amargasaurus
Tyrannosaurus
Deinonychus
Velociraptor
Mamenchisaurus

output = dinosaurs->GetRange(2, 3)->ToArray()

Amargasaurus
Tyrannosaurus
Deinonychus
 */

using System;
using System.Collections.Generic;

public class Example
{
    public static void Main()
    {
        string[] input = { "Brachiosaurus",
                           "Amargasaurus",
                           "Mamenchisaurus" };

        List<string> dinosaurs = new List<string>(input);

        Console.WriteLine("\nCapacity: {0}", dinosaurs.Capacity);

        Console.WriteLine();
        foreach( string dinosaur in dinosaurs )
        {
            Console.WriteLine(dinosaur);
        }

        Console.WriteLine("\nAddRange(dinosaurs)");
        dinosaurs.AddRange(dinosaurs);

        Console.WriteLine();
        foreach( string dinosaur in dinosaurs )
        {
            Console.WriteLine(dinosaur);
        }

        Console.WriteLine("\nRemoveRange(2, 2)");
        dinosaurs.RemoveRange(2, 2);

        Console.WriteLine();
        foreach( string dinosaur in dinosaurs )
        {
            Console.WriteLine(dinosaur);
        }

        input = new string[] { "Tyrannosaurus",
                               "Deinonychus",
                               "Velociraptor"};

        Console.WriteLine("\nInsertRange(3, input)");
        dinosaurs.InsertRange(3, input);

        Console.WriteLine();
        foreach( string dinosaur in dinosaurs )
        {
            Console.WriteLine(dinosaur);
        }

        Console.WriteLine("\noutput = dinosaurs.GetRange(2, 3).ToArray()");
        string[] output = dinosaurs.GetRange(2, 3).ToArray();

        Console.WriteLine();
        foreach( string dinosaur in output )
        {
            Console.WriteLine(dinosaur);
        }
    }
}

/* This code example produces the following output:

Capacity: 3

Brachiosaurus
Amargasaurus
Mamenchisaurus

AddRange(dinosaurs)

Brachiosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Amargasaurus
Mamenchisaurus

RemoveRange(2, 2)

Brachiosaurus
Amargasaurus
Amargasaurus
Mamenchisaurus

InsertRange(3, input)

Brachiosaurus
Amargasaurus
Amargasaurus
Tyrannosaurus
Deinonychus
Velociraptor
Mamenchisaurus

output = dinosaurs.GetRange(2, 3).ToArray()

Amargasaurus
Tyrannosaurus
Deinonychus
 */

Imports System.Collections.Generic

Public Class Example

    Public Shared Sub Main()

        Dim input() As String = { "Brachiosaurus", _
                                  "Amargasaurus", _
                                  "Mamenchisaurus" }

        Dim dinosaurs As New List(Of String)(input)

        Console.WriteLine(vbLf & "Capacity: {0}", dinosaurs.Capacity)

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

        Console.WriteLine(vbLf & "AddRange(dinosaurs)")
        dinosaurs.AddRange(dinosaurs)

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

        Console.WriteLine(vbLf & "RemoveRange(2, 2)")
        dinosaurs.RemoveRange(2, 2)

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

        input = New String() { "Tyrannosaurus", _
                               "Deinonychus", _
                               "Velociraptor" }

        Console.WriteLine(vbLf & "InsertRange(3, input)")
        dinosaurs.InsertRange(3, input)

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

        Console.WriteLine(vbLf & "output = dinosaurs.GetRange(2, 3).ToArray")
        Dim output() As String = dinosaurs.GetRange(2, 3).ToArray()
        
        Console.WriteLine()
        For Each dinosaur As String In output
            Console.WriteLine(dinosaur)
        Next

    End Sub
End Class

' This code example produces the following output:
'
'Capacity: 3
'
'Brachiosaurus
'Amargasaurus
'Mamenchisaurus
'
'AddRange(dinosaurs)
'
'Brachiosaurus
'Amargasaurus
'Mamenchisaurus
'Brachiosaurus
'Amargasaurus
'Mamenchisaurus
'
'RemoveRange(2, 2)
'
'Brachiosaurus
'Amargasaurus
'Amargasaurus
'Mamenchisaurus
'
'InsertRange(3, input)
'
'Brachiosaurus
'Amargasaurus
'Amargasaurus
'Tyrannosaurus
'Deinonychus
'Velociraptor
'Mamenchisaurus
'
'output = dinosaurs.GetRange(2, 3).ToArray
'
'Amargasaurus
'Tyrannosaurus
'Deinonychus

Remarks

List<T> accepts null as a valid value for reference types and allows duplicate elements.

If the new Count (the current Count plus the size of the collection) will be greater than Capacity, the capacity of the List<T> is increased by automatically reallocating the internal array to accommodate the new elements, and the existing elements are copied to the new array before the new elements are added.

If index is equal to Count, the elements are added to the end of List<T>.

The order of the elements in the collection is preserved in the List<T>.

This method is an O(n * m) operation, where n is the number of elements to be added and m is Count.

Applies to

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