scope of variable in nodejs inside a function

Question

How to scope datat ? Here datat is empty. And i would like to put data in a var so i can use it outside the function.

var datat;
twit.search('#louieck', {include_entities:true,page:paget,maxid:maxidt}, function(data) {

// and output to the console:

datat =  data;

});
sys.puts(sys.inspect(datat));

Regards

Bussiere

At the time you call sys.puts, the callback function hasn't been called yet so datat is empty. Welcome to the world of asynchronicity :) — robertklep
– robertklep, Commented Mar 22, 2013 at 12:29

Carol Skelly · Accepted Answer · 2013-03-22 14:27:22Z

2

'datat' is scoped outside your function. twit.search is async and therefore may not return 'data' before you check 'datat' with sys.inspect.

This should let you see datat:

var datat;
twit.search('#louieck', {include_entities:true,page:paget,maxid:maxidt}, function(data) {

    // and output to the console:
    datat =  data;
    sys.puts(sys.inspect(datat));

});

But ideally you'd use a callback like this...

var datat;
var callback = function(d){
    sys.puts(sys.inspect(d));

    datat = d;
    // do something more with datat

};

twit.search('#louieck', {include_entities:true,page:paget,maxid:maxidt}, function(data) {

    callback(data);

});

EDIT - simplified as per comment...

var datat;
var callback = function(d){
  sys.puts(sys.inspect(d));
  datat = d;
  // do something more with datat
};
twit.search('#louieck', {include_entities:true,page:paget,maxid:maxidt},callback(data));

edited Mar 22, 2013 at 14:27

answered Mar 22, 2013 at 12:35

Carol Skelly

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1 Comment

Aaron Dufour Over a year ago

In the second example, you don't need the anonymous function. Just pass callback.

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