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
Exception |
Condition |
|---|---|
Thrown 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 any, 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 7, Windows Vista SP2, Windows XP SP3, Windows XP x64 SP2, Windows Server 2008 R2, Windows Server 2008 SP2, Windows Server 2003 SP2
Version Information
F# Runtime
Supported in: 2.0, 4.0
Silverlight
Supported in: 3