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

Tests whether a sequence has any elements.

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

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

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

// Usage:
Seq.isEmpty source
source

Type: seq<'T>

The input sequence.

Exception

Condition

ArgumentNullException

Thrown when the input sequence is null.

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

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.

The following code shows how to use Seq.isEmpty.

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

Output

true
false

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

F# Core Library Versions

Supported in: 2.0, 4.0, Portable

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