title: Java syntax and terminology
body: <p>I'm extremely new to Java and Android development and recently did a quick skim over the documentation to begin learning Android development. These should be very basic clarity-questions, but I can't find the right place to search to get the answer. </p>
  
  <p>I was hopping I could get some clarification on the syntax in this android tutorial:</p>
  
  <p>All of the private variables are declared at the top of the class and prefixed with "m". Why is this? What does the m-prefix imply?</p>
  
  <pre><code>private DrawerLayout mDrawerLayout;
  </code></pre>
  
  <p>When these m-prefixed variables are declared inside of the method, why are their parent objects written with a parenthesis? </p>
  
  <pre><code>mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
  </code></pre>
  
  <p>I'm a bit confused over this because I see objects being instantiated with the <code>new</code> keyword. Is this different from what's going on above?</p>
  
  <p>And my last question, why are there arrows >&lt; wrapped around <code>String</code></p>
  
  <pre><code>new ArrayAdapter&lt;String&gt;
  </code></pre>
  
  <p>Here's the full example code</p>
  
  <pre><code>public class MainActivity extends Activity {
      private String[] mPlanetTitles;
      private DrawerLayout mDrawerLayout;
      private ListView mDrawerList;
      ...
  
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
  
          mPlanetTitles = getResources().getStringArray(R.array.planets_array);
          mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
          mDrawerList = (ListView) findViewById(R.id.left_drawer);
  
          // Set the adapter for the list view
          mDrawerList.setAdapter(new ArrayAdapter&lt;String&gt;(this,
                  R.layout.drawer_list_item, mPlanetTitles));
          // Set the list's click listener
          mDrawerList.setOnItemClickListener(new DrawerItemClickListener());
  
          ...
      }
  }
  </code></pre>