the scope of variables in AJAX requests

One question that often puzzles me is how JavaScript still retains a reference in a callback function of an AJAX request, even when the variable was declared in the function that issues the AJAX call. Here's an example:

var loadMask = {name:"test"};

form.submit({
  url: 'request.php',
  timeout : 180000,
  success: function(the_form, action_object)
  {    
    console.log(loadMask);
  }
});

Despite loadMask being declared outside of the success function, it remains visible and defined inside.

How does this work?

Answer №1

Utilizing a feature known as closures, it is indeed possible to achieve this task. There are numerous sources available for further information:

Check out some resources from a simple search on Google:

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