HashSet<T>.Contains Method
.NET Framework 4.5
Determines whether a HashSet<T> object contains the specified element.
Namespace: System.Collections.Generic
Assembly: System.Core (in System.Core.dll)
Parameters
- item
- Type: T
The element to locate in the HashSet<T> object.
Return Value
Type: System.Booleantrue if the HashSet<T> object contains the specified element; otherwise, false.
Implements
ICollection<T>.Contains(T)The following example demonstrates how to remove values from a HashSet<T> collection using the Remove method. In this example, the Contains method verifies that the set contains a value before removing it.
static void Main()
{
HashSet<int> evenNumbers = new HashSet<int>();
for (int i = 0; i < 20; i++)
{
evenNumbers.Add(i);
}
Console.Write("evenNumbers contains {0} elements: ", evenNumbers.Count);
DisplaySet(evenNumbers);
evenNumbers.RemoveWhere(isEven);
Console.Write("evenNumbers contains {0} elements: ", evenNumbers.Count);
DisplaySet(evenNumbers);
if (evenNumbers.Contains(0))
{
evenNumbers.Remove(0);
}
Console.Write("evenNumbers contains {0} elements: ", evenNumbers.Count);
DisplaySet(evenNumbers);
}
private static bool isEven(int i)
{
return ((i % 2) == 1);
}
/* This example produces output similar to the following:
* evenNumbers contains 20 elements: { 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 }
* evenNumbers contains 10 elements: { 0 2 4 6 8 10 12 14 16 18 }
* evenNumbers contains 9 elements: { 2 4 6 8 10 12 14 16 18 }
*/
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
