JAVA Interfaces and Abstract Classes Which of the following class definitions defines a legal abstract class? public class abstract A { abstract void unfinished(); } class A { abstract void unfinished() { } } abstract class A { abstract void unfinished(); } class A { abstract void unfinished(); } public class abstract A { abstract void unfinished(); } class A { abstract void unfinished() { } } abstract class A { abstract void unfinished(); } class A { abstract void unfinished(); } 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. } 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 None of these null Compilation fails due to an error on line 3 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which of the following statements regarding abstract classes are true? A subclass can override a concrete method in a superclass to declare it abstract. An abstract class can be used as a data type. All of these A subclass of a non-abstract superclass can be abstract. An abstract class can be extended. A subclass can override a concrete method in a superclass to declare it abstract. An abstract class can be used as a data type. All of these A subclass of a non-abstract superclass can be abstract. An abstract class can be extended. 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 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 b is an instance of Nothing. b is an instance of ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes 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 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 compile without any errors. This code will not compile, because class Dog must implement method doYourJob() from interface Guard. 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 compile without any errors. This code will not compile, because class Dog must implement method doYourJob() from interface Guard. ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes What will be the output when the following program is compiled and executed?abstract class TestAbstract{ String my_name; String myName(){ my_name = "Examveda"; return my_name; } abstract void display();}public class Test extends TestAbstract{ void display(){ String n = myName(); System.out.print("My name is "+ n); } public static void main(String args[]){ Test t = new Test(); t.display(); }} None of these Program will compile and execute successfully and prints Compilation error occurs as the abstract class TestAbstract contains a non-abstract method. Compilation error as class can not be declared as abstract. Program compiles but leads to runtime exception. None of these Program will compile and execute successfully and prints Compilation error occurs as the abstract class TestAbstract contains a non-abstract method. Compilation error as class can not be declared as abstract. Program compiles but leads to runtime exception. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS