Shameless plaigarism of hashp for console.log in cljs:
(ns example.core)
(defn mean [xs]
(/ (double #c (reduce + xs)) #c (count xs)))
Evaluating the form:
(mean (range 10)) ;; => 4.5
Browser console:
#c[example.core/mean::4] (reduce + xs) => 45
#c[example.core/mean::4] (count xs) => 10
The primary difference being that the output will use cljs devtools formatters if available (automatically added by shadow-cljs) to print the resulting value.
It doesn't currently print output to stdout, only to the browser console.