Just fyi indexOf is O(n), which means if you tried to do: var count = 1000000; var arr = foo(count); for (var i = 0; i < count; i++) arr[i](); It wi

Just fyi indexOf is O(n), which means if you tried to do: var count = 1000000; var arr = foo(count); for (var i = 0; i < count; i++) arr[i](); It will take O(n^2) and will probably never complete whereas all the other solutions here will probably take ~1second.