.

For interop, the . special form allows access to member properties of the given JavaScript object o.

If the second operand is a symbol preceded with a hyphen as in -p, the expression will result in the value of the property named p.

If the second operand is a symbol that is not preceded with a hyphen as in m, the expression will evaluate to a call of the method named m. Any additional operands will be passed as arguments to the method.

The preferred, idiomatic way to access members of a JavaScript object is to use the following sugar:

(.-p o)

(. o -p)

(.m o)

(. o m)

(.m o 1 2)

(. o m 1 2)

We can access the JavaScript properties of a string:

// JavaScript
var m = "Hello World";
m.length;
//=> 11

;; ClojureScript
(def m "Hello World")
(.-length m)
;;=> 11

We can also call member functions on the string:

// JavaScript
m.toUpperCase();
//=> "HELLO WORLD"

m.replace("H", "");
//=> "ello World";

;; ClojureScript
(.toUpperCase m)
;;=> "HELLO WORLD"

(.replace m "H" "")
;;=> "ello World"

Create a JavaScript object o:

(def o #js {:foo "bar"})

You can get the value at property "foo" with any of the following:

(. o -foo)
;;=> "bar"

(.-foo o)
;;=> "bar"

(aget o "foo")
;;=> "bar"