Functions
defn takes following arguments: the name of the function, a vector of parameters, and finally the body of the function.
To call the function, simply use the function with parens.
When we call a function, Clojure will evaluate it and return a result.
(defn some-thing [] "one more thing")
;; -> #'user/some-thing
(some-thing)
;; -> "one more thing"Following is a function with parameters.
(defn some-thing [foo bar] {:name "apple"
:foo foo
:bar bar})
;; -> #'user/some-thing
(some-thing "yellow" "fields")
;; -> {:name "apple", :foo "yellow", :bar "fields"} Following is an anonymous function without a name, and are expressed with fn operator. Those can be called with surrounding parens:
(fn [] (str "Ahoy" "!"))
;; -> #object[lalaland.core$eval2436$fn__2437 0x40ce6a71 "lalaland.core$eval2436$fn__2437@40ce6a71"]
;;invoke with parens
((fn [] (str "Ahoy" "!")))
;; -> "Ahoy !"defn = def + fn
(def some-thing (fn [] (str "Ahoy " "!")))
;; -> #'user/some-thing
(some-thing)
;; -> "Ahoy !"Following is shorthand form of an anonymous function. It uses a # in front.
(#(str "Ahoy" "!"))
;; -> "Ahoy !"For a single parameter, percent sign (%) to represents it.
(#(str "Hello" %) "world")
;; -> "Hello world"for multiple parameters, %1, %2 and so on represents the same
(#(str "hello" %1 %2) "foo" "bar")
;; -> "hello foo bar"