JavaScript interoperability
One of the most powerful things about ClojureScript is the ease with which one can access and interact with the JavaScript runtime. In this section, we'll take a closer look at how you can work with native JavaScript code from ClojureScript.
JavaScript collections
Odds are good that you won't want to work too much with JavaScript collections directly now that you've gotten an understanding of how powerful ClojureScript's collection objects are, but it's still important to know how to access these from ClojureScript as well as to make sure you're comfortable converting JavaScript data types to ClojureScript and vice versa. Learning about this syntax will also prove useful when calling JS libraries from ClojureScript.
Arrays
Following is an example of defining and then accessing a JavaScript array from the ClojureScript REPL:
cljs.user> (def a (array 1 2 3)) ;; => #'cljs.user/a cljs.user=> a ;; => #js [1 2 3] cljs.user...