Understanding ClojureScript functions

Before we dive too far into ClojureScript, we need to understand the syntax behind ClojureScript functions. Functions in ClojureScript work like functions in most computer languages.

Functions

Functions in ClojureScript are first-class entities, which means that we can store them as variables, or values in data structures, return them as values from other functions, and pass functions as arguments to other functions.

We'll be demonstrating quite a bit of code evaluation in this chapter. In order to follow along, start up an REPL following the instructions provided in the previous chapter.

Let's start by quickly seeing what a function call in ClojureScript looks like at the REPL:

cljs.user=> (+ 1 2)
;; => 3

ClojureScript, as a Lisp, looks unlike many other languages, including JavaScript. It is a language written in prefix notation, which means that the calling function is the first argument. The same operation, performed in JavaScript, would...