JAVA Interfaces and Abstract Classes interface Test{ int p = 10; //line 1 public int q = 20; //line 2 public static int r = 30; //line 3 public static final int s = 40; //line 4}Which of the above line will give compilation error? 1 4 3 2 None of these 1 4 3 2 None of these ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Suppose A is an abstract class, B is a concrete subclass of A, and both A and B have a default constructor. Which of the following is correct?1. A a = new A();2. A a = new B();3. B b = new A();4. B b = new B(); 2 and 3 2 and 4 1 and 2 1 and 3 3 and 4 2 and 3 2 and 4 1 and 2 1 and 3 3 and 4 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Determine output of the following code.interface A { }class C { }class D extends C { }class B extends D implements A { }public class Test extends Thread{ public static void main(String[] args){ B b = new B(); if (b instanceof A) System.out.println("b is an instance of A"); if (b instanceof C) System.out.println("b is an instance of C"); }} b is an instance of Nothing. b is an instance of b is an instance of A followed by b is an instance of b is an instance of Nothing. b is an instance of b is an instance of A followed by b is an instance of ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Given the following piece of code:public class School{ public abstract double numberOfStudent();}which of the following statements is true? Class School must be defined abstract. The method numberOfStudent() in class School must have a body. The keywords public and abstract cannot be used together. You must add a return statement in method numberOfStudent(). Class School must be defined abstract. The method numberOfStudent() in class School must have a body. The keywords public and abstract cannot be used together. You must add a return statement in method numberOfStudent(). ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes In Java, declaring a class abstract is useful To force developers to extend the class not to use its capabilities. When it doesn't make sense to have objects of that class. When default implementations of some methods are not desirable. To prevent developers from further extending the class. When it makes sense to have objects of that class. To force developers to extend the class not to use its capabilities. When it doesn't make sense to have objects of that class. When default implementations of some methods are not desirable. To prevent developers from further extending the class. When it makes sense to have objects of that class. ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which two of the following are legal declarations for abstract 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 {} 3 and 5 5 and 6 3 and 6 1 and 2 2 and 4 3 and 5 5 and 6 3 and 6 1 and 2 2 and 4 ANSWER DOWNLOAD EXAMIANS APP
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