HashSet(Of T).Add Method (T)

 

Adds the specified element to a set.

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

Public Function Add (
	item As T
) As Boolean

Parameters

item
Type: T

The element to add to the set.

Return Value

Type: System.Boolean

true if the element is added to the HashSet(Of T) object; false if the element is already present.

If Count already equals the capacity of the HashSet(Of T) object, the capacity is automatically adjusted to accommodate the new item.

If Count is less than the capacity of the internal array, this method is an O(1) operation. If the HashSet(Of T) object must be resized, this method becomes an O(n) operation, where n is Count.

The following example demonstrates how to create and populate two HashSet(Of T) objects. This example is part of a larger example provided for the UnionWith method.

HashSet<int> evenNumbers = new HashSet<int>();
HashSet<int> oddNumbers = new HashSet<int>();

for (int i = 0; i < 5; i++)
{
    // Populate numbers with just even numbers.
    evenNumbers.Add(i * 2);

    // Populate oddNumbers with just odd numbers.
    oddNumbers.Add((i * 2) + 1);
}

Universal Windows Platform
Available since 8
.NET Framework
Available since 3.5
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 4.0
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1
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