Collection<'T>.Contains Method ('T)
Determines whether an element is in the Collection<'T>.
Assembly: mscorlib (in mscorlib.dll)
Parameters
- item
-
Type:
T
The object to locate in the Collection<'T>. The value can be null for reference types.
Implements
ICollection<'T>.Contains('T)If the Collection<'T> object is created using the default constructor, this method determines equality using the default equality comparer EqualityComparer<'T>.Default for T, the type of values in the list. If type T does not implement the IEquatable<'T> interface, the Equals method is used.
If the Collection object is created by passing an IList<'T> object to the constructor, the Contains method will be determined by the IEqualityComparer<'T> interface used by that IList<'T> object.
This method performs a linear search; therefore, the average execution time is proportional to Count. That is, this method is an O(n) operation, where n is Count.
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