clojure.core/not-empty

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Type: function Added: Clojure 1.0 Examples: 4 Runnable: 4

([coll])

If coll is empty, returns nil, else coll

Examples

by OnesimusUnbound on 2011-07-27 ▶

(not-empty [1]) [1] (not-empty [1 3 5]) [1 3 5] (not-empty []) nil (not-empty '()) nil (not-empty {}) nil (not-empty nil) nil

by joshdegagne on 2016-12-05 ▶

;; Same behaviour for strings (not-empty "hello") "hello" (not-empty "") nil

by kopos on 2020-04-08 ▶

;; if-let can now work with colls also, not being limited to scalar values alone (if-let [valid (not-empty (filter even? [2 4 6]))] valid) (2 4 6) ;; if-let helps avoid another nested if check (if-let [valid (not-empty (filter even? [1 3 5]))] valid) nil ;; without not-empty we would have to work with another if conditional (if-let [valid (filter even? [1 3 5])] valid) ()

by iGEL on 2024-11-18 ▶

;; The difference to seq is, that it doesn't change the ;; type of collection if it's not empty: (seq #{1 2 3}) ;; -> (1 3 2) (seq [1 2 3]) ;; -> (1 2 3) (not-empty #{1 2 3}) ;; -> #{1 3 2} (not-empty [1 2 3]) ;; -> [1 2 3]

See also

• clojure.core/empty (1)
• clojure.core/empty? (5)
• clojure.core/seq (5)

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