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)
[ExtensionAttribute] public: generic<typename TSource> static int Count( IEnumerable<TSource>^ source, Func<TSource, bool>^ predicate )
The type of the elements of source.
- Type: System.Collections.Generic::IEnumerable<>
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.
Usage NoteIn Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable<>. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).
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.
Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.