control structure

Question

Finding difficult understanding following control structure

scala> def twice(op: Double => Double, x: Double) = op(op(x))

twice: (op: (Double) => Double,x: Double)Double

scala> twice( _ + 1,5)

res0: Double = 7.0

Hmm. Your question is not very precise. What exactly don't you understand? — Madoc, Feb 04 '11 at 16:05
That's a funny one because of the formatting, at least for people accustomed to ',' as decimal separator. :) — mkneissl, Feb 05 '11 at 09:32

score 3 · Accepted Answer · answered Feb 04 '11 at 15:55

3

op: Double => Double

is a function that takes a Double and returns a Double as a result. twice is a method takes a number, calls op on it, and then calls op on the result.

_ + 1

is a function that takes a value and adds one to it.

You can probably figure out the rest from there.

answered Feb 04 '11 at 15:55

Rex Kerr

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Maybe my brain wasn't working..got confused w.r.t placeholder..but got it now...Thanks – Amit Feb 04 '11 at 16:19

control structure

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