JAVA Interfaces and Abstract Classes Which of the following statements regarding abstract classes are true? A subclass of a non-abstract superclass can be abstract. All of these 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. A subclass of a non-abstract superclass can be abstract. All of these 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. 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 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 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. This code will compile without any errors. This code will not compile, because method doYourJob() in interface Guard must be defined abstract. ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes 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. 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. 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 as the display method is not declared as abstract. 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 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 as the display method is not declared as abstract. 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 declaration of the display method has been provided in two interface. The code will compile and execute successfully showing the output Welcome to Examians. 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()); }} test-name Compilation succeed but Runtime Exception Compilation fails due to an error on lines 2 None of these Compilation fails due to an error on lines 1 test-name Compilation succeed but Runtime Exception Compilation fails due to an error on lines 2 None of these Compilation fails due to an error on lines 1 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();}} compiles fine but print nothing None of these Compilation Error will print Class Two method will print Class One method compiles fine but print nothing None of these Compilation Error will print Class Two method will print Class One method ANSWER DOWNLOAD EXAMIANS APP
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