JS Bin// source http://jsbin.com/diqumox

jsbin.diqumox.js

/** Default Function Arguments */
// Example #1
function makeAjaxRequest(url, method = 'GET') {
  return method;
}
console.log(makeAjaxRequest('google.com'));

// Example #2
function User(id) {
  this.id = id;
}

function genereateId () {
    return Math.random().toString(36).substring(2) + (new Date()).getTime().toString(36);
}

function createAdminUser(user = new User(genereateId())) {
  user.admin = true;

  return user;
}

function addOffset(style = {offset: '10px'}) {
  return style;
}