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vectors done

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Oli Clive-Griffin 2021-06-03 13:46:00 +12:00
parent 1feb28923b
commit 9ea2e0473c
1 changed files with 10 additions and 10 deletions
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20
src/koans/04_vectors.clj
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@ -3,31 +3,31 @@
(meditations
"You can use vectors in clojure as array-like structures"
(= __ (count [42]))
(= 1 (count [42]))
"You can create a vector from a list"
(= __ (vec '(1)))
(= [1] (vec '(1)))
"Or from some elements"
(= __ (vector nil nil))
(= [nil nil] (vector nil nil))
"But you can populate it with any number of elements at once"
(= [1 __] (vec '(1 2)))
(= [1 2] (vec '(1 2)))
"Conjoining to a vector is different than to a list"
(= __ (conj [111 222] 333))
(= [111 222 333 ] (conj [111 222] 333))
"You can get the first element of a vector like so"
(= __ (first [:peanut :butter :and :jelly]))
(= :peanut (first [:peanut :butter :and :jelly]))
"And the last in a similar fashion"
(= __ (last [:peanut :butter :and :jelly]))
(= :jelly (last [:peanut :butter :and :jelly]))
"Or any index if you wish"
(= __ (nth [:peanut :butter :and :jelly] 3))
(= :jelly (nth [:peanut :butter :and :jelly] 3))
"You can also slice a vector"
(= __ (subvec [:peanut :butter :and :jelly] 1 3))
(= [:butter :and] (subvec [:peanut :butter :and :jelly] 1 3))
"Equality with collections is in terms of values"
(= (list 1 2 3) (vector 1 2 __)))
(= (list 1 2 3) (vector 1 2 3)))