js pattern for async calls

gistfile1.js

var future = function(d) { 
  var obj = {}; 
  obj.val = 0; 

  setTimeout(function(){ obj.val=d;}, 5000); 

  return obj;  
}

var result = future(4); 
console.log(result.val)  // returns 0

// after 5 seconds
console.log(result.val) // returns 4