Seq.iter2<'T1,'T2> Function (F#)

Article
04/28/2015

Applies the given function to two collections simultaneously. If one sequence is shorter than the other then the remaining elements of the longer sequence are ignored.

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

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

// Signature:
Seq.iter2 : ('T1 -> 'T2 -> unit) -> seq<'T1> -> seq<'T2> -> unit

// Usage:
Seq.iter2 action source1 source2

Parameters

action
Type: 'T1 -> 'T2 ->unit

A function to apply to each pair of elements from the input sequences.
source1
Type: seq<'T1>

The first input sequence.
source2
Type: seq<'T2>

The second input sequence.

Exceptions

Exception	Condition
ArgumentNullException	Thrown when either of the input sequences is null.

Remarks

This function is named Iterate2 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.iter2 and compares its behavior to related functions.

let seq1 = [1; 2; 3]
let seq2 = [4; 5; 6]
Seq.iter (fun x -> printfn "Seq.iter: element is %d" x) seq1
Seq.iteri(fun i x -> printfn "Seq.iteri: element %d is %d" i x) seq1
Seq.iter2 (fun x y -> printfn "Seq.iter2: elements are %d %d" x y) seq1 seq2

Output

Seq.iter: element is 1
Seq.iter: element is 2
Seq.iter: element is 3
Seq.iteri: element 0 is 1
Seq.iteri: element 1 is 2
Seq.iteri: element 2 is 3
Seq.iter2: elements are 1 4
Seq.iter2: elements are 2 5
Seq.iter2: elements are 3 6

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

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