InsertRange Method

List<T>.InsertRange Method (Int32, IEnumerable<T>)


Inserts the elements of a collection into the List<T> at the specified index.

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

public void InsertRange(
	int index,
	IEnumerable<T> collection


Type: System.Int32

The zero-based index at which the new elements should be inserted.

Type: System.Collections.Generic.IEnumerable<T>

The collection whose elements should be inserted into the List<T>. The collection itself cannot be null, but it can contain elements that are null, if type T is a reference type.

Exception Condition

collection is null.


index is less than 0.


index is greater than Count.

List<T> accepts null as a valid value for reference types and allows duplicate elements.

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 index is equal to Count, the elements are added to the end of List<T>.

The order of the elements in the collection is preserved in the List<T>.

This method is an O(n + m) operation, where n is the number of elements to be added and m is Count.

The following example demonstrates InsertRange method and various other methods of the List<T> class that act on ranges. After the list has been created and populated with the names of several peaceful plant-eating dinosaurs, the InsertRange method is used to insert an array of three ferocious meat-eating dinosaurs into the list, beginning at index location 3.

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Universal Windows Platform
Available since 4.5
.NET Framework
Available since 2.0
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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