Is This Proper Java?

glenng · May 19th, 2011, 08:53 AM

Is is acceptable in java to declare and type variables inside a while loop? This from Chapter 7 code:

Code:

if (toDoListCursor.moveToFirst())
    		do {
    			String task = toDoListCursor.getString(ToDoDBAdapter.TASK_COLUMN);
    			long created = toDoListCursor.getLong(ToDoDBAdapter.CREATION_DATE_COLUMN);
    			ToDoItem newItem = new ToDoItem(task, new Date(created));
    			todoItems.add(0, newItem);
    		} while (toDoListCursor.moveToNext());
    	aa.notifyDataSetChanged();

Should not

Code:

String task; long created; ToDoItem newItem;

appear before the loop and then just assignments made inside the loop? Seems like the loop will be creating hundreds of variables this way, unless Java somehow manages that automatically.

DrGaribaldi · May 25th, 2011, 02:52 PM

It's proper Java. Variables should always be declared within the "tightest" scope possible. They don't get re-declared each time through the loop -- one copy of each variable is allocated each time the containing method is called.