One example is when you want to pass a function as param to another function. JavaScript example: Forced to use named function: var greaterThanFunction = func

One example is when you want to pass a function as param to another function. JavaScript example: Forced to use named function: var greaterThanFunction = function(a, b) { return a > b; }; var filteredResults = filter(biglist, greatherThanFunction); VS: Anonymous: var filteredResults = filter(biglist, function(a, b) { return a > b; }); The JavaScript example above is nice, but in Clojure anonymous lambdas are even nicer: You can do things like: (reduce #(+ %1 %2) (range 1000)) i.e., not only do you not have to name the function, you don't even have to name the variables. ---- Excerpt from http://clojure.org/reader http://clojure.org/reader Anonymous function literal (#()) #(...) => (fn [args] (...)) where args are determined by the presence of argument literals taking the form %, %n or %&. % is a synonym for %1, %n designates the nth arg (1-based), and %& designates a rest arg. This is not a replacement for fn - idiomatic used would be for very short one-off mapping/filter fns and the like. #() forms cannot be nested.