clojure.core/keyword

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Type: function Added: Clojure 1.0 Examples: 11 Runnable: 7

([name] [ns name])

Returns a Keyword with the given namespace and name. Do not use : in the keyword strings, it will be added automatically.

Examples

by dakrone on 2010-07-31 ▶

;; (keyword name): name can be string, symbol, or keyword. ;; ;; (keyword ns name): ns and name must both be string. ;; ;; A keyword string, like a symbol, begins with a non-numeric ;; character and can contain alphanumeric characters and *, +, !, -, ;; _, and ?. (see http://clojure.org/reader for details). ;; ;; keyword does not validate input strings for ns and name, and may ;; return improper keywords with undefined behavior for non-conformant ;; ns and name. (keyword 'foo) :foo (keyword "foo") :foo (keyword "user" "foo") :user/foo ;; keyword in current namespace (keyword (str *ns*) "foo") :user/foo

by franks42 on 2012-03-13 . May have evaluation errors. ▶

;; some gotchas to be aware of: (keyword "user" 'abc) ClassCastException clojure.lang.Symbol cannot be cast to java.lang.String clojure.core/keyword (core.clj:558) (keyword *ns* "abc") ClassCastException clojure.lang.Namespace cannot be cast to java.lang.String clojure.core/keyword (core.clj:558) (keyword 'user "abc") ClassCastException clojure.lang.Symbol cannot be cast to java.lang.String clojure.core/keyword (core.clj:558) ;; Warning - the following generated keywords are non-conformant and may wreak ;; serious havoc in the near/far future when least expected... ;; Even if `keyword?` might return true for them and they seem to work with ;; `name` and `namespace` as well, and they can be used as functions ;; (e.g. `(:/// {:/// "x"})` works), problems usually come at e.g. destructuring... (keyword "abc def") :abc def (keyword "123def") :123def (keyword "/abc/def/ghi") :/abc/def/ghi (keyword ":" ":") ::/: (keyword "/" "/") :/// (keyword "") : (keyword "" "/") :// (keyword "...") :...

by Phalphalak on 2014-02-17 . May have evaluation errors. ▶

;; You can define namespaced keywords using '::' (def a :foo) #'user/a (def b ::foo) #'user/b (ns foo) user/a :foo user/b :user/foo ::foo :foo/foo (= user/a :foo) true (= user/b ::foo) false (= user/b :user/foo) true

by ShayMatasaro on 2015-10-26 ▶

;;only convert strings (keyword 1) nil (keyword '1) nil

by PetrGlad on 2016-12-20 ▶

(keyword "my.key") ;=> :my.key (qualified-keyword? :my.key) ;=> nil ;; "my.key" is just name, dot does not count (keyword "my.namespace" "my.key") ;=> :my.namespace/my.key (qualified-keyword? :my.namespace/my.key) ;=> true (namespace :my.namespace/my.key) ;=> "my.namespace" (name :my.namespace/my.key) ;=> "my.key"

by phreed on 2018-01-30 ▶

;; let's make an illustrative namespace (create-ns 'my.arbitrary.long.namespace) (alias 'maln 'my.arbitrary.long.namespace) ;; more typically loaded and aliased with require ;; (require '[my.arbitrary.long.namespace :as maln]) ;; Qualified keywords may be specified with the namespace or the alias. ;; But unlike with symbols where the bare alias is used ;; you need to prefix the alias with '::' :my.arbitrary.long.namespace/foo ;=> :my.arbitrary.long.namespace/foo ::maln/bar ;=> :my.arbitrary.long.namespace/bar

by troglotit on 2018-05-31 . May have evaluation errors. ▶

;; You can use existing keywords (cljs only) (keyword :namespace :keyword) ;;=> :namespace/keyword (keyword "namespace" :keyword) ;;=> :namespace/keyword (keyword :namespace "keyword") ;;=> :namespace/keyword (keyword :meta-namespace/namespace :meta-keyword/keyword) ;;=> :namespace/keyword

by cljlc on 2019-01-26 ▶

;; different (non-conformant) keywords can have the same printed representation: (= :a/b/c (keyword "a" "b/c")) ;;=> true (keyword "a/b" "c") ;;=> :a/b/c (= (str (keyword "a/b" "c")) (str (keyword "a" "b/c"))) ;;=> true (= (keyword "a/b" "c") (keyword "a" "b/c")) ;;=> false

by luiszambon on 2020-09-06 ▶

(defn creating-map [key value] {(keyword key) value}) (:map-key (creating-map "map-key" "map-value")) ;;=>"map-value"

by jkndrkn on 2022-01-07 ▶

;; Be careful because it is possible to create keywords that contain whitespace (keyword "my-keyword\t") ;;=> :my-keyword (name (keyword "my-keyword\t")) ;;=> "my-keyword\t" (= (keyword "my-keyword") :my-keyword) ;;=> true (= (keyword "my-keyword\t") :my-keyword) ;;=> false

by bombaywalla on 2025-11-17 . May have evaluation errors. ▶

;; A string with a slash happens to create a namespace qualified keyword ;; Do not rely on this behavior (qualified-keyword? (keyword "foo/bar")) ;;=> true (let [x (keyword "foo/bar")] (println "ns:" (namespace x)) (println "name:" (name x))) ns: foo name: bar ;;=> nil

See also

• clojure.core/name (4)
• clojure.core/keyword?
• clojure.core/namespace (1)
• clojure.core/find-keyword
• clojure.core/symbol (0)

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