clojure.core/fn?

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

([x])

Returns true if x implements Fn, i.e. is an object created via fn.

Examples

by dpritchett on 2010-07-14 ▶

(fn? 5) false (fn? inc) true (fn? (fn [])) true (fn? #(5)) true

by Dimagog on 2010-07-15 ▶

;; Even though maps, sets, vectors and keywords behave as functions: ({:a 1} :a) 1 ;; fn? still returns false for them because they are not created using fn: (fn? {:a 1}) false

Note by bfontaine

Note fn? only tests if something was created using fn, not if it’s a function. Use ifn? for that. Some things are functions even though they weren’t created with fn, such as maps, vectors and keywords.

See also

• clojure.core/ifn?

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