Add a dropdown list to any button. Make sure that the
          data-target attribute matches the id in the
          <ul> tag. You can add a divider with the
          <li class="divider"></li> tag. You can also add icons. Just add the icon inside the
          anchor tag.
  <!-- Dropdown Trigger -->
  <a class='dropdown-trigger btn' href='#' data-target='dropdown1'>Drop Me!</a>
  <!-- Dropdown Structure -->
  <ul id='dropdown1' class='dropdown-content'>
    <li><a href="#!">one</a></li>
    <li><a href="#!">two</a></li>
    <li class="divider" tabindex="-1"></li>
    <li><a href="#!">three</a></li>
    <li><a href="#!"><i class="material-icons">view_module</i>four</a></li>
    <li><a href="#!"><i class="material-icons">cloud</i>five</a></li>
  </ul>
        
      Initialization
  document.addEventListener('DOMContentLoaded', function() {
    var elems = document.querySelectorAll('.dropdown-trigger');
    var instances = M.Dropdown.init(elems, options);
  });
  // Or with jQuery
  $('.dropdown-trigger').dropdown();
        
      Options
| Name | Type | Default | Description | 
|---|---|---|---|
| alignment | String | 'left' | Defines the edge the menu is aligned to. | 
| autoTrigger | Boolean | true | If true, automatically focus dropdown el for keyboard. | 
| constrainWidth | Boolean | true | If true, constrainWidth to the size of the dropdown activator. | 
| container | Element | null | Provide an element that will be the bounding container of the dropdown. | 
| coverTrigger | Boolean | true | If false, the dropdown will show below the trigger. | 
| closeOnClick | Boolean | true | If true, close dropdown on item click. | 
| hover | Boolean | false | If true, the dropdown will open on hover. | 
| inDuration | Number | 150 | The duration of the transition enter in milliseconds. | 
| outDuration | Number | 250 | The duration of the transition out in milliseconds. | 
| onOpenStart | Function | null | Function called when dropdown starts entering. | 
| onOpenEnd | Function | null | Function called when dropdown finishes entering. | 
| onCloseStart | Function | null | Function called when dropdown starts exiting. | 
| onCloseEnd | Function | null | Function called when dropdown finishes exiting. | 
Methods
Because jQuery is no longer a dependency, all the methods are called on the plugin instance. You can get the plugin instance like this:
var instance = M.Dropdown.getInstance(elem); /* jQuery Method Calls You can still use the old jQuery plugin method calls. But you won't be able to access instance properties. $('.dropdown-trigger').dropdown('methodName'); $('.dropdown-trigger').dropdown('methodName', paramName); */
.open();
Open dropdown.
  instance.open();
        
        .close();
Close dropdown.
  instance.close();
        
        .recalculateDimensions();
While dropdown is open, you can recalculate its dimensions if its contents have changed.
  instance.recalculateDimensions();
        
        .destroy();
Destroy plugin instance and teardown
  instance.destroy();
        
      Properties
| Name | Type | Description | 
|---|---|---|
| el | Element | The DOM element the plugin was initialized with. | 
| options | Object | The options the instance was initialized with. | 
| id | String | ID of the dropdown element. | 
| dropdownEl | Element | The DOM element of the dropdown. | 
| isOpen | Boolean | If the dropdown is open. | 
| isScrollable | Boolean | If the dropdown content is scrollable. | 
| focusedIndex | Number | The index of the item focused. | 
