JavaScript function with optional arguments and default values

js-function-with-optional-arguments

/*
 * Exmaple for how to use a JavaScript function with optional arguments
 * (1)  define default values in object as key-value pairs
 * (2)  compare default_options with options and add default value if a 
 *      key is not present in options
 * (3)  do what you want to do with your function
*/
function doSomething(options) {
  var default_options = {
    'option1' : true,
    'option2' :	"Value2",
    'option3' :	"Value3",
    'option4' :	"Value4"
  }

  for(var key in default_options) {
    if(typeof options[key] == "undefined") options[key] = default_options[key];
  }
	
  // do stuff
	
}

doSomething({
  'option1' : false,
  'option2' : "ValueX",
  'option4' : "ValueY"
});