CODEWITHSUNDEEP
vectorclojure
Ezekiel
Ezekiel

Reputation: 187

Separate a single vector of vectors into individual vectors in clojure

I have a single vector of vectors and I want to separate them into individual vectors.

[["1" "2" "3"] ["a" "b" "c"]]
;;=> ["1" "2" "3"] ["a" "b" "c"]

[["1" "2" "3"] ["a" "b" "c"] ["10" "20" "30"]]
;=> ["1" "2" "3"] ["a" "b" "c"] ["10" "20" "30"]

Upvotes: 0

Views: 275

Answers (1)

Leon Grapenthin
Leon Grapenthin

Reputation: 9266

You already have individual vectors inside of your vector. A variety of ways exist to access them, most notably nth.

Separation can happen in many ways. Here are some examples that you can try out at a REPL.

A common pattern is to use let with to bind them individually in a local context:

(let [first-elem (nth my-vec 0)
      third-elem (nth my-vec 2)]
  (str "First: " first-elem "\Third: " third-elem))

This is often done via destructoring, too:

(let [[first-elem _ third-elem] my-vec] ;; _ is idiomatic for ignored binding
  (str "First: " first-elem "\Third: " third-elem))

Another common scenario is building a lazy sequence from the individual elements, like:

(map-indexed (fn [i v] (str "Elem " i ": " v)) my-vec)

Or just iteration for side-effects

(doseq [v my-vec]
  (println v))
;; in Clojure 1.7 prefer
(run! println my-vec)

Or storing one as mutable state

(def current-choice (atom nil))
(swap! current-choice (nth my-vec 2))
@current-choice

You will discover many more as you learn about Clojure collections. Continue experimentation at will.

Upvotes: 2

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