But again main doubt why TextView resource id it needs?
Look at the constructor and the params.
public ArrayAdapter (Context context, int resource, int textViewResourceId, T[] objects)
Added in API level 1 Constructor
Parameters
context
The current context.
resource
The resource ID for a layout file containing a layout to use when instantiating views.
textViewResourceId
The id of the TextView within the layout resource to be populated objects The objects to represent in theListView
.
android.R.id.text1
refers to the id of text in android resource. So you need not have the one in your activity.
Here's the full list
http://developer.android.com/reference/android/R.id.html
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, android.R.id.text1, values);
this
refers to activity context
android.R.layout.simple_list_item_1
simple_list_item_1 is the layout in android.R.layout.
android.R.id.text1
refers to the android resource id.
values
is a string array from the link you provided
http://developer.android.com/reference/android/R.layout.html