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List(Of T).AddRange Method

Adds the elements of the specified collection to the end of the List(Of T).

Namespace:  System.Collections.Generic
Assemblies:   mscorlib (in mscorlib.dll)
  System.Collections (in System.Collections.dll)

'Declaration
Public Sub AddRange ( _
	collection As IEnumerable(Of T) _
)

Parameters

collection
Type: System.Collections.Generic.IEnumerable(Of T)

The collection whose elements should be added to the end of the List(Of T). The collection itself cannot be Nothing, but it can contain elements that are Nothing, if type T is a reference type.

ExceptionCondition
ArgumentNullException

collection is Nothing.

The order of the elements in the collection is preserved in the List(Of T).

If the new Count (the current Count plus the size of the collection) will be greater than Capacity, the capacity of the List(Of 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 the List(Of T) can accommodate the new elements without increasing the Capacity, this method is an O(n) operation, where n is the number of elements to be added. If the capacity needs to be increased to accommodate the new elements, this method becomes an O(n + m) operation, where n is the number of elements to be added and m is Count.

The following example demonstrates the AddRange method and various other methods of the List(Of T) class that act on ranges. An array of strings is created and passed to the constructor, populating the list with the elements of the array. The AddRange method is called, with the list as its argument. The result is that the current elements of the list are added to the end of the list, duplicating all the elements.

Imports System
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

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0

Portable Class Library

Supported in: Portable Class Library

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8
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