CODEWITHSUNDEEP
clojure
jordz_dunn
jordz_dunn

Reputation: 33

List Prime Numbers within a range results in an error message in Clojure

I am so close to having this cracked, but I cannot see what I'm missing. is-prime? should return true if the number inputted is a prime number or it should return false if the number is not prime. The function I have created works great apart from it will not return false for the number 1. As part of the spec, I was told to set both numbers 1 and 2 which is what I tried doing but it doesn't seem to be doing anything.

  (defn is-prime? [n]
  (if (= n 1) false)
  (if (= n 2) no-divisors?)
  (no-divisors? n)
)

Here is a list of all the inputs and expected outcomes for is-prime? The only one that returns incorrect is(is-prime? 1).

   (is-prime? 1)
=> false
   (is-prime? 2)
=> true
   (is-prime? 3)
=> true
   (is-prime? 4)
=> false
   (is-prime? 101)
=> true

Upvotes: 0

Views: 128

Answers (1)

akond
akond

Reputation: 16045

In clojure the result of a function is its last expression, so in your example (if (= n 1) false) and (if (= n 2) no-divisors?) are always lost, because the last expression is (no-divisors? n).

Try this:

(defn is-prime? [n]
    (cond 
       (= n 1) false
       (= n 2) true
       :else (no-divisors? n)))

Upvotes: 1

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