The examples given for the use of (let are leaving me confused. I think I understand what (let is for, but in the context of the example, isn't it unnecessary?
(let ((x (* a a)) (y (* b b)))
(+ x y)))
(sum-sq 3 4) → 25
(define (sum-sq a b) ; alternative syntax
(let (x (* a a) y (* b b))
(+ x y)))
Wouldn't this make more sense in defining a sum-of-squares routine?
(+ (* a a) (* b b)))
I know it doesn't demonstrate the use of (let, but (let seems unnecesssary: I checked, and a and b don't seem to be affected outside this function. So what's the point of using (let to isolate values here? Or is it just an artificial example and I shouldn't worry so much? ;-)
Quote
Yes, absolutely, the example has been kept simple for didactic purposes.
Lutz
Quote from: "Lutz"
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Yes, absolutely, the example has been kept simple for didactic purposes.
Lutz
Thanks, just making sure I wasn't missing something.
gc
The point is to localise x and y, not a and b.
e.g. suppose x and y were created with
(set 'x (* a a))
(set 'y (* b b))
(+ x y))
(println (sum-sq 3 4))
(println x)
(println y)
In this case x and y continue to exist outside of the scope they were created in (whereas they would not in the