This document contains 30 questions about Java programming concepts including: - Methods for starting a thread and thread states - Access modifiers like private, protected, and public - Relationships between classes like Canvas and Graphics - Syntax elements like packages and import statements - Exceptions and exception handling - Inheritance and polymorphism

1. JAVA QUESTIONS 6
1. What method is invoked to cause an object to begin executing as a separate
thread?
2. Name two subclasses of the TextComponent class.
3. Which containers may have a MenuBar?
4. How are commas used in the intialization and iteration parts of a for statement?
5. What is the purpose of the wait(), notify(), and notifyAll() methods?
6. What is an abstract method?
7. How are Java source code files named?
8. What is the relationship between the Canvas class and the Graphics class?
9. What are the high-level thread states?
10.What value does read() return when it has reached the end of a file?
11.What is the return type of a program's main() method?
12.If a variable is declared as private, where may the variable be accessed?
13.What do you understand by private, protected and public?
14.What is Downcasting ?
15.What modifiers may be used with an inner class that is a member of an outer
class?
16.How many bits are used to represent Unicode, ASCII, UTF-16, and UTF-8
characters?
17.What restrictions are placed on the location of a package statement within a
source code file?
18.What is a native method?
19.What are order of precedence and associativity, and how are they used?
20.Can an anonymous class be declared as implementing an interface and
extending a class?
21.Can an unreachable object become reachable again?
22.What method must be implemented by all threads?
23.What are synchronized methods and synchronized statements?
24.What is Externalizable?
25.What modifiers are allowed for methods in an Interface?
26.What are some alternatives to inheritance?
27.What does it mean that a method or field is "static"?
28.What is the difference between preemptive scheduling and time slicing?
29.What is the catch or declare rule for method declarations?
30.Is Empty .java file a valid source file?