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 1 and 2 2 and 4 3 and 4 1 and 3 2 and 3 1 and 2 2 and 4 3 and 4 1 and 3 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 2 and 4 1 and 2 3 and 6 3 and 5 5 and 6 2 and 4 1 and 2 3 and 6 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes What happens if the following program is compiled and executed?interface MyInterface{ void display();}interface MySubInterface extends MyInterface{ void display();}public class Test implements MySubInterface{ public void display(){ System.out.print("Welcome to Examveda."); } public static void main(String args[]){ Test t = new Test(); t.display(); }} The code will lead to a compilation error due to public modifier while declaring the display method. The code will lead to a compilation error as the display method is not declared as abstract. The code will lead to a compilation error as declaration of the display method has been provided in two interface. The code will compile and execute successfully showing the output Welcome to Examians. None of these The code will lead to a compilation error due to public modifier while declaring the display method. The code will lead to a compilation error as the display method is not declared as abstract. The code will lead to a compilation error as declaration of the display method has been provided in two interface. The code will compile and execute successfully showing the output Welcome to Examians. None of these ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes What is the output for the below code ?interface A{ public void printValue();}1. public class Test{2. public static void main (String[] args){3. A a1 = new A(){4. public void printValue(){5. System.out.println("A");6. }7. };8. a1.printValue();9. }10. } None of these null Compilation fails due to an error on line 3 Compilation fails due to an error on line 8 A None of these null Compilation fails due to an error on line 3 Compilation fails due to an error on line 8 A ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes What will be the output?1. public interface InfA{2. protected String getName();3. }public class Test implements InfA{ public String getName(){ return "test-name"; } public static void main (String[] args){ Test t = new Test(); System.out.println(t.getName()); }} Compilation succeed but Runtime Exception Compilation fails due to an error on lines 2 test-name None of these Compilation fails due to an error on lines 1 Compilation succeed but Runtime Exception Compilation fails due to an error on lines 2 test-name None of these Compilation fails due to an error on lines 1 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"); }} Nothing. b is an instance of A followed by b is an instance of b is an instance of b is an instance of Nothing. b is an instance of A followed by b is an instance of b is an instance of b is an instance of ANSWER DOWNLOAD EXAMIANS APP
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