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(); 1 and 3 3 and 4 2 and 3 2 and 4 1 and 2 1 and 3 3 and 4 2 and 3 2 and 4 1 and 2 ANSWER DOWNLOAD EXAMIANS APP
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? 2 None of these 3 4 1 2 None of these 3 4 1 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which of the following statements regarding abstract classes are true? A subclass of a non-abstract superclass can be abstract. A subclass can override a concrete method in a superclass to declare it abstract. All of these An abstract class can be extended. An abstract class can be used as a data type. A subclass of a non-abstract superclass can be abstract. A subclass can override a concrete method in a superclass to declare it abstract. All of these An abstract class can be extended. An abstract class can be used as a data type. ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes What will be the output for the below code ?public interface TestInf{ int i =10;}public class Test{ public static void main(String... args){ TestInf.i=12; System.out.println(TestInf.i); }} 10 12 None of these Runtime Exception Compile with error 10 12 None of these Runtime Exception Compile with error 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 6 1 and 2 5 and 6 3 and 5 2 and 4 3 and 6 1 and 2 5 and 6 3 and 5 2 and 4 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? 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(). 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. ANSWER DOWNLOAD EXAMIANS APP
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