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 1 and 3 2 and 3 3 and 4 1 and 2 2 and 4 1 and 3 2 and 3 3 and 4 1 and 2 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 One method will print Class Two method None of these compiles fine but print nothing Compilation Error will print Class One method will print Class Two method None of these compiles fine but print nothing Compilation 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 {} 5 and 6 3 and 5 1 and 2 2 and 4 3 and 6 5 and 6 3 and 5 1 and 2 2 and 4 3 and 6 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 compile without any errors. 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. This code will not compile, because method doYourJob() in interface Guard must be defined abstract. This code will compile without any errors. 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. ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes In Java, declaring a class abstract is useful When it doesn't make sense to have objects of that class. To prevent developers from further extending the class. 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. When it doesn't make sense to have objects of that class. To prevent developers from further extending the class. 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. ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Runnable is a _____ . method abstract class interface class vaiable method abstract class interface class vaiable ANSWER DOWNLOAD EXAMIANS APP
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