Clojure Koans 5 Sets Notebook

{:hello (clojure-version)}

;; "You can create a set by converting another collection"

(= #{3} (set '(3)))

;; skill 5001: convert a list or vector into a set using the `set` function

;; "Counting them is like counting other collections"

(= 3 (count #{1 2 3}))

;; skill 5002: Find the quantity of items in a collection by using the `count` function

;; skill 5003: Find the quantity of items in a set by using the `count` function

;; "Remember that a set is a *mathematical* set"

(= #{1 2 3 4 5} (set '(1 1 2 2 3 3 4 4 5 5)))

;; skill 5004: Remove duplicates from a collection by converting it to a set

;; "You can ask clojure for the union of two sets"

(= #{1 2 3 4 5} (set/union #{1 2 3 4} #{2 3 5}))

;; skill 5005: Combine (join? unite?) two sets into one using the `clojure.set/union` function

;; "And also the intersection"

(= #{2 3} (set/intersection #{1 2 3 4} #{2 3 5}))

;; skill 5006: Intersect two sets using the `clojure.set/intersection` function

;; "But don't forget about the difference"

(= #{1 4} (set/difference #{1 2 3 4 5} #{2 3 5})))

;; skill 5007: Get the difference of two sets using the `clojure.set/difference` function