Use apply on native JavaScript functions

Question

In clojureScript the following multi-arity function

(defn sum [& xs] (reduce + xs))

can be either called via (sum 4 6 9) or by the use of (apply sum [4 6 9]) which yields the same result.

How can this be done with a native JavaScript function, such as: console.log .

(apply js/console.log [1 2 3])

This, yields the following error:

#object[TypeError TypeError: 'log' called on an object that does not implement interface Console.]

Answer 1

Some browsers always assuming the this is certain object, you can use .bind in js for temporal fix.

; you can use .bind on any function
(def d (.bind (.-log js/console) js/console))
(def ms ["aaa" "bbb" "barbarbar"])
(mapv d ms)

Related questions

What does this statement do? console.log.bind(console)

Why do js functions fail when I assign them to a local variable?

Answer 2

There might be an error in your code. apply works totally fine out of the box for JS functions:

cljs.user=> (apply js/Math.sqrt [25])
5

You can test it with this online REPL and I also tested it in my local project -- no problems so far.

cljs.user=> (apply js/console.log [1 2 3])
nil

also prints the output in the normal JS console as expected.

Answer 3

Using js/ab only works when a is global in your environment. Either way, I find this much cleaner:

(apply (.-log js/console) [1 2 3])

Note: with member functions, don't forget the first argument is this .