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Enumerable.LongCount(TSource) Method (IEnumerable(TSource))

Returns an Int64 that represents the total number of elements in a sequence.

Namespace:  System.Linq
Assemblies:   System.Linq (in System.Linq.dll)
  System.Core (in System.Core.dll)

static member LongCount : 
        source:IEnumerable<'TSource> -> int64

Type Parameters

TSource

The type of the elements of source.

Parameters

source
Type: System.Collections.Generic.IEnumerable(TSource)

An IEnumerable(T) that contains the elements to be counted.

Return Value

Type: System.Int64
The number of elements in the source sequence.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable(TSource). 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).

ExceptionCondition
ArgumentNullException

source is a null reference (Nothing in Visual Basic).

OverflowException

The number of elements exceeds MaxValue.

Use this method rather than Count when you expect the result to be greater than MaxValue.

In Visual Basic query expression syntax, an Aggregate Into LongCount() clause translates to an invocation of LongCount.

The following code example demonstrates how to use LongCount(TSource)(IEnumerable(TSource)) to count the elements in an array.

No code example is currently available or this language may not be supported.

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Portable Class Library

Supported in: Portable Class Library
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