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how to access the 2nd element in a tuple
f#

if i got a tuple list like seqA = seq[(1,2), (2,3)...]

i can do something like:

let (a,b) = Seq.hd seqA

if b=2 then doSomething

is there a way to write those two-line code into one line?

something like:

if (Seq.hd seqA).secondelement = 2 then doSomething...

.

Use pattern matching:

match (Seq.hd seqA) with

| (_, 2) -> doSomething

| _ -> doSomethingElse

By on 6/3/2009 10:47 PM ()

let seqA = seq [(1, 2); (3, 4)]

let b = snd (Seq.hd seqA)

By on 6/17/2009 1:32 PM ()

For 2-tuples, the functions 'fst' and 'snd' get the first and second elements respectively.

For larger tuples, you have to use pattern matching (but can easily define your own functions based on that, e.g.

let fstOf3 (x,y,z) = x

).

By on 6/3/2009 10:33 PM ()

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