How do I find the index of an item in a vector?

Question

Any ideas what ???? should be? Is there a built in? What would be the best way to accomplish this task?

(def v [\"one\" \"two\" \"three\" \"two         


        

Answer 1

(defn find-thing [needle haystack]
  (keep-indexed #(when (= %2 needle) %1) haystack))

But I'd like to warn you against fiddling with indices: most often than not it's going to produce less idiomatic, awkward Clojure.