List<T>.AddRange(IEnumerable<T>) Method
Definition
Important
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Adds the elements of the specified collection to the end of the List<T>.
public:
void AddRange(System::Collections::Generic::IEnumerable<T> ^ collection);
public void AddRange (System.Collections.Generic.IEnumerable<T> collection);
member this.AddRange : seq<'T> -> unit
Public Sub AddRange (collection As IEnumerable(Of T))
Parameters
- collection
- IEnumerable<T>
The collection whose elements should be added to the end of 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
collection
is null
.
Examples
The following example demonstrates the AddRange method and various other methods of the List<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.
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
The order of the elements in the collection is preserved in the List<T>.
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 the List<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.