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

Parameters

• source
  Type: seq<'T>

  The input sequence.

Exceptions

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

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

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

Reference

Collections.Seq Module (F#)

Microsoft.FSharp.Collections Namespace (F#)