Given the following piece of code:public interface Guard{ void doYourJob();}abstract public class Dog implements Guard{ }which of the following statements is correct? This code will compile without any errors. This code will not compile, because method doYourJob() in interface Guard must be defined abstract. This code will not compile, because in the declaration of class Dog we must use the keyword extends instead of implements. This code will not compile, because class Dog must implement method doYourJob() from interface Guard. TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following is a correct interface? interface A { void print() { } } abstract interface A { abstract void print(); { }} interface A { void print(); } abstract interface A { print(); } TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following statements regarding abstract classes are true? All of these A subclass can override a concrete method in a superclass to declare it abstract. An abstract class can be used as a data type. A subclass of a non-abstract superclass can be abstract. An abstract class can be extended. TRUE ANSWER : ? YOUR ANSWER : ?
In Java, declaring a class abstract is useful To force developers to extend the class not to use its capabilities. When default implementations of some methods are not desirable. When it makes sense to have objects of that class. To prevent developers from further extending the class. When it doesn't make sense to have objects of that class. TRUE ANSWER : ? YOUR ANSWER : ?
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); }} Runtime Exception 12 None of these Compile with error 10 TRUE ANSWER : ? YOUR ANSWER : ?
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 3 1 and 2 2 and 4 3 and 4 TRUE ANSWER : ? YOUR ANSWER : ?
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 Compilation fails due to an error on line 8 Compilation fails due to an error on line 3 A null TRUE ANSWER : ? YOUR ANSWER : ?
What will happen after compiling this program code?abstract class MyClass{ //line 1 private int a, b; public void call(int a, int b){ this.a = a; this.b = b; System.out.print(a+b); }}public class Test{ public static void main(String args[]){ MyClass m = new MyClass(); //line 2 m.call(12,25); }} Compilation error due to line 1 Compilation error due to line 2 Runtime error None of these Successful run and print 37 TRUE ANSWER : ? YOUR ANSWER : ?
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();}} Compilation Error will print Class Two method None of these will print Class One method compiles fine but print nothing TRUE ANSWER : ? YOUR ANSWER : ?
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 as the display method is not declared as abstract. None of these 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 declaration of the display method has been provided in two interface. TRUE ANSWER : ? YOUR ANSWER : ?