JSON, Loop and updating variables at same time

[intellix]

Hey guys... quick question

 

I have jQuery using JSON to pull in aload of data...

Within the JSON request, when it returns data, I have a loop that adds stuff to an object and then updates the page... It uses a variable I want to update at the same time.

 

If I make the request and I start playing with the site, I want the function at the end of the loop to use the latest data (as JSON isn't instant and I don't want to lock the page from the user updating it)... Can I update the variable whilst the JSON request, loop is running and then when it gets to the end of it, the variable will be updated? Or does JavaScript work on a queue sort of basis where it will finish the JSON request, loop first until I can start updating variables that will be used at the end of it all?

 

Thanks, Dom

[intellix]

Also in terms of performance... Say if I have a 250kb JSON script pulled and put into an object like:

 

var $largeData = jsondata;

 

Once I've done with it, do you think its good to set it to null or something to free memory? Or is this done automatically and not needed?