clojure.core/dissoc

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Type: function Added: Clojure 1.0 Examples: 5 Runnable: 3

([map] [map key] [map key & ks])

dissoc[iate]. Returns a new map of the same (hashed/sorted) type, that does not contain a mapping for key(s).

Examples

by zmila on 2010-07-28 ▶

(dissoc {:a 1 :b 2 :c 3}) ; dissoc nothing ;;=> {:a 1, :b 2, :c 3} (dissoc {:a 1 :b 2 :c 3} :b) ; dissoc key :b ;;=> {:a 1, :c 3} (dissoc {:a 1 :b 2 :c 3} :d) ; dissoc not existing key ;;=> {:a 1, :b 2, :c 3} (dissoc {:a 1 :b 2 :c 3} :c :b) ; several keys at once ;;=> {:a 1}

by timgilbert on 2015-09-13 ▶

;; There is no (dissoc-in) analogous to (get-in) or (assoc-in), but ;; you can achieve a similar effect using (update-in): (update-in {:a {:b {:x 3} :c 1}} [:a :b] dissoc :x) ;;=> {:a {:b {}, :c 1}}

by skuro on 2017-04-21 . May have evaluation errors. ▶

;; When applied to a record and one of its base fields, ;; dissoc produces a plain map instead of a record (defrecord Widget [id]) (def w (->Widget "id")) (class w) ;; user.Widget (class (dissoc w :id)) ;; clojure.lang.PersistentArrayMap

by RobinNagpal on 2018-01-17 . May have evaluation errors. ▶

;; Removing multiple from nested map (update-in {:a {:b {:x 3 :y 5} :c 1}} [:a :b] (fn [nested] (apply dissoc nested [:x :y] )) ) => {:a {:b {}, :c 1}}

by Em-AK on 2020-12-15 ▶

;; dissoc keys in a coll (reduce dissoc {:a 1 :b 2 :c 3} [:b :c]) {:a 1} ;; Can also use apply, a bit slower; any seqable works for either of these (apply dissoc {:a 1 :b 2 :c 3} #{:b :c}) {:a 1}

Note by u473t8

(update {} :a dissoc :b) => {:a nil}

See also

• clojure.core/assoc (8)
• clojure.core/disj (2)
• clojure.core/select-keys (5)
• clojure.core/update-in (10)
• clojure.core/remove (6)

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