clojure.core/def

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Type: var Added: Clojure unknown Examples: 8 Runnable: 4

()

Creates and interns or locates a global var with the name of symbol and a namespace of the value of the current namespace (ns). See http://clojure.org/special_forms for more information.

Examples

by boxie on 2010-11-06 . May have evaluation errors. ▶

(def my-val 5) #'user/my-val my-val 5

by boxie on 2010-11-06 . May have evaluation errors. ▶

(def my-function (fn [x] (* x x x))) #'user/my-function (my-function 4) 64

by puredanger on 2011-03-22 . May have evaluation errors. ▶

;; This is an example of setting a docstring during a def. ;; (Note that the clojure.repl namespace which contains the ;; doc function is not loaded by default in Emacs' SLIME mode.) (def ted-nugent "The nuge rocks" 123) #'user/ted-nugent (doc ted-nugent) ------------------------- user/ted-nugent The nuge rocks ted-nugent 123

by jamesqiu on 2011-08-16 ▶

;; give function another name (def sys-map map) ;; give macro another name (def #^{:macro true} sys-loop #'loop)

by ibercode on 2018-02-16 ▶

;;Assign a Function to a Variable (def say-hello (fn [name] (str "Hello " name))) (say-hello "World") ;;"Hello World" ;;the same but using an anonymous function (def say-hello #(str "Hello " %)) (say-hello "World") ;;"Hello World" ;;anonymous function using two arguments (def hello-doc #(str "Hello " %1 %2)) (hello-doc "Dr." "House") ;;"Hello Dr.House"

by deadghost on 2021-12-21 ▶

;; Private var (def ^:private foobar "I am the docstring." "I am the value.")

by clojer on 2022-06-09 . May have evaluation errors. ▶

;; function checks: variable = 9 or not (def ?9 #(= % 9)) #'user/?9 (?9 9) true (?9 5) false

by siddharthjain-in on 2024-04-08 ▶

; add a doc-string to your def variable (def my-var "this is doc string for my var" "hello") ; add a doc-string using meta key `:doc` (def ^{:doc "this is doc string for my var"} my-var "hello")

See also

• clojure.core/defn (5)
• clojure.core/fn (3)
• clojure.core/defmacro (2)
• clojure.core/defmulti (7)
• clojure.core/defonce (0)
• clojure.core/ns-unmap

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