title: Angular how to pass optional constructor arguments skipping some
body: <p>My constructor in angular2 has a lot of parameters which are optional .Its like a search construct. When passing parameters , how can i say this parameters is this ? 
  Suppose if there is first-name,last-name,age,sex which are all optional. I have to just pass sex without passing any other things. It looks like passing a parameter with a name. I dont want to pass null and by pass things.</p>
  
  <p>Thanks</p>