List<'T>.CopyTo Method (Int32, 'T[], Int32, Int32)
Copies a range of elements from the List<'T> to a compatible one-dimensional array, starting at the specified index of the target array.
Assembly: mscorlib (in mscorlib.dll)
Parameters
- index
-
Type:
System.Int32
The zero-based index in the source List<'T> at which copying begins.
- array
-
Type:
'T[]
The one-dimensional Array that is the destination of the elements copied from List<'T>. The Array must have zero-based indexing.
- arrayIndex
-
Type:
System.Int32
The zero-based index in array at which copying begins.
- count
-
Type:
System.Int32
The number of elements to copy.
| Exception | Condition |
|---|---|
| ArgumentNullException | array is null. |
| ArgumentOutOfRangeException | index is less than 0. -or- arrayIndex is less than 0. -or- count is less than 0. |
| ArgumentException |
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 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.
Available since 8
.NET Framework
Available since 2.0
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1