clojure.core/nil?

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

([x])

Returns true if x is nil, false otherwise.

Examples

by dpritchett on 2010-07-14 ▶

(nil? nil) true (nil? 0) false (nil? false) false (nil? '()) false

by phreed on 2017-10-26 ▶

;; as nil? is defined as "Returns true if x is nil, false otherwise." ;; and some? is defined as "Returns true if x is not nil, false otherwise." ;; (some? x) is just shorthand for (not (nil? x)) ;; this also means that nil? is the same as (not (some? x)) as this ;; just expands into (not (not (nil? x))). (def nil?? (complement some?)) ;;#'user/nil?? (for [x [nil 0 false [] '()]] (= (nil? x) (nil?? x))) ;;=> (true true true true true)

See also

• clojure.core/identity (6)
• clojure.core/some? (4)

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