Remove the last char from a string is a simple and common task, there are standard function for this, but its easy to write your own.
Method 1
(join "" (drop-last "hello"))
Method 2
(defn remove-last [str] (.substring (java.lang.String. str) 0 (- (count str) 1)) ) (remove-last "hello")
Clojure
Clojure Internals