What is the difference between :while and :when in clojure?

Question

I\'m studying clojure but not quite clear on the difference between the :while and :when test:

=> (for [x [1 2 3] y [1 2 3] :while          


        

Answer 1

Look at the last example here: http://clojuredocs.org/clojure_core/clojure.core/for#example_913