List<T>.CopyTo Method (T[])
Copies the entire List<T> to a compatible one-dimensional array, starting at the beginning of the target array.
Assembly: mscorlib (in mscorlib.dll)
| Exception | Condition |
|---|---|
| ArgumentNullException |
array is null. |
| ArgumentException |
The number of elements in the source List<T> is greater than the number of elements that the destination array can contain. |
This method uses Array.Copy to copy the elements.
The elements are copied to the Array in the same order in which the enumerator iterates through the List<T>.
This method is an O(n) operation, where n is Count.
The following code example demonstrates all three overloads of the CopyTo method. A List<T> of strings is created and populated with 5 strings. An empty string array of 15 elements is created, and the CopyTo(T[]) method overload is used to copy all the elements of the list to the array beginning at the first element of the array. The CopyTo(T[], Int32) method overload is used to copy all the elements of the list to the array beginning at array index 6 (leaving index 5 empty). Finally, the CopyTo(Int32, T[], Int32, Int32) method overload is used to copy 3 elements from the list, beginning with index 2, to the array beginning at array index 12 (leaving index 11 empty). The contents of the array are then displayed.
using System; using System.Collections.Generic; public class Example { public static void Main() { List<string> dinosaurs = new List<string>(); dinosaurs.Add("Tyrannosaurus"); dinosaurs.Add("Amargasaurus"); dinosaurs.Add("Mamenchisaurus"); dinosaurs.Add("Brachiosaurus"); dinosaurs.Add("Compsognathus"); Console.WriteLine(); foreach(string dinosaur in dinosaurs) { Console.WriteLine(dinosaur); } // Declare an array with 15 elements. string[] array = new string[15]; dinosaurs.CopyTo(array); dinosaurs.CopyTo(array, 6); dinosaurs.CopyTo(2, array, 12, 3); Console.WriteLine("\nContents of the array:"); foreach(string dinosaur in array) { Console.WriteLine(dinosaur); } } } /* This code example produces the following output: Tyrannosaurus Amargasaurus Mamenchisaurus Brachiosaurus Compsognathus Contents of the array: Tyrannosaurus Amargasaurus Mamenchisaurus Brachiosaurus Compsognathus Tyrannosaurus Amargasaurus Mamenchisaurus Brachiosaurus Compsognathus Mamenchisaurus Brachiosaurus Compsognathus */
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.
