CODEWITHSUNDEEP
functionrecursionclojure
user4813927
user4813927

Reputation:

Recursive functions in clojure

How does this recursive function work step by step:

(fn foo [n]
  (if (< n 10)
    [n]
    (conj (foo (quot n 10))
          (mod n 10))))

I have problem with understanding: lets say i give it as n the number 123, and it will return a vector of its digits. At the last step when arrived to 1 and (< 1 10) it should go to the then-part [n], return [1] and come out of the recursion. So this doesn't happen, what am i missing in the play?

Upvotes: 0

Views: 112

Answers (1)

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Reputation: 13483

At the last step when arrived to 1 and (< 1 10) it does go to the then-part [n], return [1], but it does NOT come out of the recursion, only out of the innermost invocation.

The evaluation goes as follows:

(foo 123)
(conj (foo 12) 3)
(conj (conj (foo 1) 2) 3)
(conj (conj [1] 2) 3)
(conj [1 2] 3)
[1 2 3]

Upvotes: 2

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