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Seq.isEmpty<'T> Function (F#)

Den Delimarsky|Last Updated: 7/25/2016
|
1 Contributor

Tests whether a sequence has any elements.

Namespace/Module Path: Microsoft.FSharp.Collections.Seq

Assembly: FSharp.Core (in FSharp.Core.dll)

Syntax

// Signature:
Seq.isEmpty : seq<'T> -> bool

// Usage:
Seq.isEmpty source

Parameters

source Type: seq<'T>

The input sequence.

Exceptions

ExceptionCondition
ArgumentNullExceptionThrown when the input sequence is null.

Return Value

true if the input sequence is empty. Otherwise, returns false.

Remarks

The first element of the source sequence, if there is one, is evaluated on each call. To avoid this, you can create a cached sequence by using Seq.cache.

This function is named IsEmpty in compiled assemblies. If you are accessing the function from a .NET language other than F#, or through reflection, use this name.

Example


let emptySeq = Seq.empty
let nonEmptySeq = seq { 1 .. 10 }
Seq.isEmpty emptySeq |> printfn "%b"
Seq.isEmpty nonEmptySeq |> printfn "%b"

Output

true
false

Platforms

Windows 8, Windows 7, Windows Server 2012, Windows Server 2008 R2

Version Information

F# Core Library Versions

Supported in: 2.0, 4.0, Portable

See Also

Collections.Seq Module (F#)

Microsoft.FSharp.Collections Namespace (F#)

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