How do I set a variable in a function using Javascript or jQuery

Question

I need to move the data out of HTML code and load it on demand.

I need to do something like this:

function processData( data )
{
   if ( data.length===0 )
   {         
      data = get data from server using Ajax or even...
      data = [['2011-06-01',1],['2011-06-02',3]] ; // just for educational purposes
   }
   else go do stuff with data ;
} 

storeData = [] ;
processData( storeData ) ; // first time storeData doesn't contain any data
processData( storeData ) ; // now storeData contains data

I can't figure out how to stuff the data from within the function. Is there a way of accomplishing this?

Community · Accepted Answer · 2020-06-20 09:12:55Z

1

function processData()
{
   if ( storeData.length===0 )
   {         
      storeData = get data from server using Ajax
   }
   else go do stuff with storeData ;
} 

storeData = [] ;
processData( storeData ) ; // first time storeData doesn't contain any data
processData( storeData ) ; // now storeData contains data

storeData is a global anyway. When you specify processData( data ) you are doing what's called a pass by value. Basically your making a copy of the data. Once the program exits the function, the copy is lost to garbage collection. An alternative would be to pass by reference, but because it's a global anyway (declared outside the function) there's little point.

Edit

read here

http://snook.ca/archives/javascript/javascript_pass

edited Jun 20, 2020 at 9:12

CommunityBot

11 silver badge

answered Jul 28, 2011 at 21:34

Joseph Marikle

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Comments

JZC · Accepted Answer · 2011-07-28 21:40:50Z

0

It might help to know more concrete details since it seems like you might be going about your task in an unusual way. There may be a better way of accomplishing what you want.

Have you just tried something as simple as:

function processData( data )
{
    ...
    return data;
} 

storeData = [] ;
storeData = processData( storeData ) ; // first time storeData doesn't contain any data
storeData = processData( storeData ) ; // now storeData contains data

answered Jul 28, 2011 at 21:40

JZC

4705 silver badges13 bronze badges

1 Comment

JZC Over a year ago

Not elegant, but you could have the function return two values (an array of 2 values), one containing the jPlot object and the other containing the data. Also, it sounds like the other Joseph that answered your question has a good solution.

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