scjp MCQ Question and Answer
scjp MCQ Question and Answer
21. Read the following code excerpt carefully
- A.java cannot be compiled. Duplicate defination of inner class B.
- A.java compiles without any error. An attempt to run C as an application will cause runtime linkage error. Duplicate definations of inner class B are found
- Only one class file corresponding to the inner class B is created in the file system.
- Two class files corresponding to both inner classes (B) is created in the file system.
22. Attempting to compile and run the code will cause
- Compiler error - abstract classes cannot have constructors.
- Compiler error - the method AbstractClass does not have a valid return type.
- Compiler error - the class cannot be declared as abstract as it does not have any unimplemented methods.
- No compiler error - the class is practically not an abstract class and can be instantiated.
23. Read the following piece of code carefully.
- It can be achived by placing the call to the superclass with a super keyword , which is placed in a try block with a catch block to handle the IOException thrown by the super class.
- It can be achived by avoiding explicit calls to the base class constructor.
- It cannot be done in the Java Laungage with the above definition of the base class.
24. Read the following piece of code carefully
- will cause a compiler error. The non-abstract classes cannot be extended to the abstract classes.
- will cause a compiler error. The abstract classes cannot have constructors defined.
- will not cause any compiler error. The lines "Message 1..." and "Message 3 ... " are printed on the screen.
- will not cause any compiler error. The lines "Message 1..." and "Message 2...." and Message 3...." are printed on the screen.
25. Read the following piece of code carefully.
- The class A can be referenced outside the package in which it is defined.
- The class A cannot be instantiated outside the package in which it is defined.
- The class A cannot be extended outside the package in which it is defined.
- The class A can be referenced, instantiated or extended anywhere.
26. If a Runtime Exception is thrown in the finalize method
- The running application crashes
- The exception is simply ignored and the object is garbage collected.
- The exception is simply ignored, but the object is not garbage collected.
- The Exception causes the JVM to crash.
27. The factory class java.util.Collections
- is public
- implements the java.util.Collection interface.
29. What does the following expression print on the screen?
System.out.println(Math.min(Float.NaN, Float.POSITIVE_INFINITY));
- NaN
- Infinity
- The expression throws a runtime exception - NaN is an illegal argument.
30. What does the following expression return
Math.max(Float.POSITIVE_INFINITY,Double.POSITIVE_INFINITY);
- Float.POSITIVE_INFINITY
- Double.POSITIVE_INFINITY
- runtime Exception