ClojureScript 检查属性是否存在于 js 对象中

Question

如何在 clojurescript 中编写以下内容？

obj = {"a" : 4};
"a" in obj;

Answer 1

存在吗？是 added检查 undefined在 ClojureScript 中:

   (ns my.ns
     (:require-macros [cljs.core :refer [exists?]]))

   (if (exists? js/jQuery)
      (println "jQuery"))
      (println "no jQuery"))

也可以用 aget和 nil?避免调用 JavaScript 函数:

(def scope (js-obj))
(aset scope "var1" "Value")
(aget scope "var1")               ;; "Value"
(aget scope "anotherVar")         ;; nil
(nil? (aget scope "anotherVar"))  ;; true