Enumerable.Count<'TSource> Method (IEnumerable<'TSource>, Func<'TSource, Boolean>)
Returns a number that represents how many elements in the specified sequence satisfy a condition.
Assembly: System.Core (in System.Core.dll)
static member Count<'TSource> : source:IEnumerable<'TSource> * predicate:Func<'TSource, bool> -> int
A sequence that contains elements to be tested and counted.
Return ValueType: System.Int32
A number that represents how many elements in the sequence satisfy the condition in the predicate function.
The type of the elements of source.
If the type of source implements ICollection<'T>, that implementation is used to obtain the count of elements. Otherwise, this method determines the count.
In Visual Basic query expression syntax, an Aggregate Into Count() clause translates to an invocation of Count.
Available since 8
Available since 3.5
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Available since 8.1