Which two of the following are legal declarations of an abstract class and interfaces

Which two of the following are legal declarations for nonnested classes and interfaces?

1 final abstract class Test {}

2 public static interface Test {}

3 final public class Test {}

4 protected abstract class Test {}

5 protected interface Test {}

6 abstract public class Test {}

[A].	1 and 4
[B].	2 and 5
[C].	3 and 6
[D].	4 and 6

Answer: Option C

Explanation:

(3), (6). Both are legal class declarations.

(1) is wrong because a class cannot be abstract and final—there would be no way to use such a class. (2) is wrong because interfaces and classes cannot be marked as static. (4) and (5) are wrong because classes and interfaces cannot be marked as protected.

Page 2

Page 3

A Compilation fails due to an error on line 3
B A
C Compilation fails due to an error on line 8
D null

Page 4

A test-name
B Compilation fails due to an error on lines 1
C Compilation fails due to an error on lines 2
D Compilation succeed but Runtime Exception

Page 5

Page 6

A Program will compile and execute successfully and prints
B Compilation error as class can not be declared as abstract.
C Program compiles but leads to runtime exception.
D Compilation error occurs as the abstract class TestAbstract contains a non-abstract method.

Page 7

A The code will lead to a compilation error as declaration of the display method has been provided in two interface.
B The code will lead to a compilation error due to public modifier while declaring the display method.
C The code will compile and execute successfully showing the output Welcome to Examveda.
D The code will lead to a compilation error as the display method is not declared as abstract.

Page 8

A Thread(Runnable threadOb, int priority)
B Thread(int priority)
C Thread(Runnable threadOb, String threadName)
D Thread(String threadName, int priority)

Page 9

A start()
B run()
C init()
D go()

Page 10

A Extending the thread class.
B Implementing Runnable interface.
C Both of the above
D None of these

Page 11

A The program does not compile because this cannot be referenced in a static method.
B The program compiles fine, but it does not print anything because t does not invoke the run() method
C The program compiles and runs fine and displays test on the console.
D None of the above

Page 12

A The program will not compile because it does not implement the run() method.
B The program will not compile because it does not contain abstract methods.
C The program compiles fine.
D None of the above

Page 13

A run-a
B run-a run-a
C Compilation fails with an error at line 6
D Compilation succeed but Runtime Exception

Page 14

A run-test run-test
B run-test
C Compilation fails due to an error on line 4
D Compilation fails due to an error on line 7

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Page 16

A The program has a compilation error because t is defined in both the main() method and the constructor Test().
B The program compiles fine, but it does not run because you cannot use the keyword this in the constructor.
C The program compiles and runs and displays nothing.
D The program compiles and runs and displays test.