gistfile1.js

function AttArg(options) {

  if (!options) var options = {};

  // a default value is given in case the options object doesn't contain an option

  var option_one = options.option_one || 1
  var option_two = options.option_two || 2
  
  // do something
  
  return [option_one, option_two];
}

// now you run the function like this

AttArg({
  option_one: "one",
  option_two: "two",
});

// will return ["one", "two"];

//or without an options object

AttArg();

// the default values will be returned [1, 2]