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List<T> Constructor (IEnumerable<T>)

Initializes a new instance of the List<T> class that contains elements copied from the specified collection and has sufficient capacity to accommodate the number of elements copied.

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

public List(
	IEnumerable<T> collection
)

Parameters

collection
Type: System.Collections.Generic.IEnumerable<T>
The collection whose elements are copied to the new list.

ExceptionCondition
ArgumentNullException

collection is null.

The elements are copied onto the List<T> in the same order they are read by the enumerator of the collection.

This constructor is an O(n) operation, where n is the number of elements in collection.

The following code example demonstrates the List<T> constructor and various 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 Capacity property is then displayed, to show that the initial capacity is exactly what is required to hold the input elements.


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
 */


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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