clojure.core/if-not

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Type: macro Added: Clojure 1.0 Examples: 3 Runnable: 2

([test then] [test then else])

Evaluates test. If logical false, evaluates and returns then expr, otherwise else expr, if supplied, else nil.

Examples

by zmila on 2010-07-30 . May have evaluation errors. ▶

(defn has-neg [coll] (if-not (empty? coll) ;; = (if (not (empty? coll)) ... (or (neg? (first coll)) (recur (rest coll))))) #'user/has-neg (has-neg []) nil (has-neg [1 2 -3 4]) true

by zmila on 2010-07-30 ▶

(if-not (zero? 0) :then :else) :else

by jafingerhut on 2012-04-13 ▶

;; See examples for "if" explaining Clojure's idea of logical true ;; and logical false.

See also

• clojure.core/if (2)
• clojure.core/when-not (5)

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