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 4 3 and 4 2 and 3 1 and 2 1 and 3 2 and 4 3 and 4 2 and 3 1 and 2 1 and 3 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(); }} None of these 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. 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. None of these 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. 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. 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 {} 1 and 2 3 and 5 2 and 4 3 and 6 5 and 6 1 and 2 3 and 5 2 and 4 3 and 6 5 and 6 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Runnable is a _____ . method abstract class interface vaiable class method abstract class interface vaiable class 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 b is an instance of b is an instance of A followed by b is an instance of Nothing. b is an instance of 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 What will be the output?interface A{public void method();}class One{public void method(){System.out.println("Class One method");}}class Two extends One implements A{public void method(){System.out.println("Class Two method");}}public class Test extends Two{public static void main(String[] args){A a = new Two();a.method();}} will print Class Two method None of these will print Class One method compiles fine but print nothing Compilation Error will print Class Two method None of these will print Class One method compiles fine but print nothing Compilation Error ANSWER DOWNLOAD EXAMIANS APP
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