Java Java Basics - Technical Questions and Answers

11.	What if the main() method is declared as private?
	Answer: The program compiles properly but at runtime it will give "main() method not public." message. Workspace Report errors ... Name : Email: View Answer

12.	What if the static modifier is removed from the signature of the main() method?
	Answer: Program compiles. But at runtime throws an error "NoSuchMethodError". Workspace Report errors ... Name : Email: View Answer

13.	What if I write static public void instead of public static void?
	Answer: Program compiles and runs properly. Workspace Report errors ... Name : Email: View Answer

14.	What if I do not provide the String array as the argument to the method?
	Answer: Program compiles but throws a runtime error "NoSuchMethodError". Workspace Report errors ... Name : Email: View Answer

15.	What is the first argument of the String array in main() method?
	Answer: The String array is empty. It does not have any element. This is unlike C/C++ where the first element by default is the program name. Workspace Report errors ... Name : Email: View Answer

16.	If I do not provide any arguments on the command line, then the String array of main() method will be empty or null?
	Answer: It is empty. But not null. Workspace Report errors ... Name : Email: View Answer

17.	How can one prove that the array is not null but empty using one line of code?
	Answer: Print args.length. It will print 0. That means it is empty. But if it would have been null then it would have thrown a NullPointerException on attempting to print args.length. Workspace Report errors ... Name : Email: View Answer

18.	What environment variables do I need to set on my machine in order to be able to run Java programs?
	Answer: CLASSPATH and PATH are the two variables. Workspace Report errors ... Name : Email: View Answer

19.	Can an application have multiple classes having main() method?
	Answer: Yes it is possible. While starting the application we mention the class name to be run. The JVM will look for the Main method only in the class whose name you have mentioned. Hence there is not conflict amongst the multiple classes having main() method. Workspace Report errors ... Name : Email: View Answer

20.	Can I have multiple main() methods in the same class?
	Answer: No the program fails to compile. The compiler says that the main() method is already defined in the class. Workspace Report errors ... Name : Email: View Answer