Question

I want to supply a default value which can be overridden. I know I can use a ternary, like this:

(def foo (if (not (nil? bar)) bar baz))

But surely there is a more idiomatic way in Clojure to say “use bar, or baz if bar is nil.

Any suggestions?

Answer 1

This will assign bar unless it is nil or false, and baz otherwise.

(def foo (or bar baz))

EDIT

If you wish to check for nil precisely, you can slightly optimize your original code, like this:

(def foo (if (nil? bar) baz bar))

I believe, this is the shortest possible way, though not idiomatic.