I've been looking at the Android development tutorials and after looking through some code, I've noticed the following:
HeadlinesFragment mHeadlinesFragment; mHeadlinesFragment = (HeadlinesFragment) getSupportFragmentManager().findFragmentById( R.id.headlines); I am fairly new to Java so that may be the issue, but why is this explicit casting of (HeadlinesFragment) necessary? Is mHeadlinesFragment not already of type HeadlinesFragment?
Thanks!
getSupportFragmentManager().findFragmentById( R.id.headlines); this returns a Fragment Object, and HeadlinesFragment is sub class, of Fragment class, and everytime you assign an object of superclass to a reference of subclass you need to cast explicitly.
You dont need explicit casting when you are assigning a subclass object to super class reference, like assigning:
List<String> list=new ArrayList<String>(); 
TextView view = (TextView)findViewById(R.id.some_text); What jeet is saying makes sense, because, if you think about it, its a lot easier to return a View, rather than think of some way to always know what a user will need returned, which you can't do`. So you make the programmer explicitly cast it saying, "I know what I'm doing."