clojure.core/vec

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Type: function Added: Clojure 1.0 Examples: 2 Runnable: 1

([coll])

Creates a new vector containing the contents of coll. Java arrays will be aliased and should not be modified.

Examples

by dpritchett on 2010-07-14 ▶

(vec '(1 2 3)) [1 2 3] (vec [1 2 3]) [1 2 3] (vec #{1 2 3}) [1 2 3] (vec {:a 1 :b 2 :c 3}) [[:a 1] [:b 2] [:c 3]] (vector {:a 1 :b 2 :c 3}) [{:a 1, :b 2, :c 3}] (vec '()) [] (vec nil) []

by jafingerhut on 2012-04-15 . May have evaluation errors. ▶

;; Warning. If the arg is a Java array, then the returned vector will alias it, ;; and modifying the array will thus modify the vector. To avoid this, do ;; not modify the array after the vec call. One way to guarantee this is to ;; make a copy of the array, call vec on the new array, and then lose all ;; references to the copy so it cannot be accessed in any way. (def a (to-array (repeat 4 0))) #'user/a (seq a) (0 0 0 0) (def v (vec a)) #'user/v v [0 0 0 0] ;; Now change a, and v changes, too, since they share state. (aset a 2 -5) -5 v [0 0 -5 0] ;; One way to avoid this (def v (vec (aclone a))) #'user/v v [0 0 -5 0] (aset a 2 -20) -20 v [0 0 -5 0]

See also

• clojure.core/vector (3)
• clojure.core/vector? (2)
• clojure.core/vector-of

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