如何计算Clojure中数组中的映射？

Question

How do I get the number of maps in the following?

[{:a "a"} {:b "b"}]

I'm expecting 2 .

Answer 1

Just use count :

(def data [{:a "a"} {:b "b"}] )
(count data) => 2

You may also be interesed in these websites:

• The Clojure CheatSheet
• Brave Clojure

Answer 2

Create a df(definition)and assign the variable to (atom 0) and count within doseq.

eg (df count-var (atom 0)) (doseq [n vec-of-maps]

(swap! cnt-var + 1))