This function is used to set the value of a reference to a new value irrespective of whatever is the older value.
Following is the syntax.
(ref-set refname newvalue)
Parameters − ‘refname’ is the name of the variable holding the reference value. ‘newvalue’ is the new value that needs to be associated with the reference type.
Return Value − The reference and its corresponding new value.
An example on how this is used is shown in the following program.
(ns clojure.examples.example (:gen-class)) (defn Example  (def my-ref (ref 1 :validator pos?)) (dosync (ref-set my-ref 2)) (println @my-ref)) (Example)
The above program produces the following output.