On Sat, Mar 21, 2009 at 9:50 AM, David-Sarah Hopwood <[email protected]> wrote: > Why is it better to use 'this' than to simply have the callback function > capture the variables it needs? It's nice to be able to consistently refer to the same 'this' from an prototype's function whether from inside a local lambda or another function on that prototype. Any generic function that takes 2 arguments and returns 1 can be used for reduce, but if that callback if a prototype's function, its 'this' will be wrong unless you provided extra code to bind the function to an object.
Yes, you can achieve this in other ways by just binding the callback to the object before passing it to reduce, so one minor benefit is that it's more compact: [].reduce(fn, init, this) [].reduce(fn.bind(this), init) But the main reason is just consistency with the rest of the functions that take a callback. Ed _______________________________________________ Es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
