[removed] Object Rename Key

Question

Is there a clever (i.e. optimized) way to rename a key in a javascript object?

A non-optimized way would be:

o[ new_key ] = o[ old_key ];
delete o[ o         


        

Answer 1

I would say that it would be better from a conceptual point of view to just leave the old object (the one from the web service) as it is, and put the values you need in a new object. I'm assuming you are extracting specific fields at one point or another anyway, if not on the client, then at least on the server. The fact that you chose to use field names that are the same as those from the web service, only lowercase, doesn't really change this. So, I'd advise to do something like this:

var myObj = {
    field1: theirObj.FIELD1, 
    field2: theirObj.FIELD2,
    (etc)
}

Of course, I'm making all kinds of assumptions here, which may not be true. If this doesn't apply to you, or if it's too slow (is it? I haven't tested, but I imagine the difference gets smaller as the number of fields increases), please ignore all of this :)

If you don't want to do this, and you only have to support specific browsers, you could also use the new getters to also return "uppercase(field)": see http://robertnyman.com/2009/05/28/getters-and-setters-with-javascript-code-samples-and-demos/ and the links on that page for more information.

EDIT:

Incredibly, this is also almost twice as fast, at least on my FF3.5 at work. See: http://jsperf.com/spiny001