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 extended. An abstract class can be used as a data type. All of these A subclass of a non-abstract superclass can be abstract. A subclass can override a concrete method in a superclass to declare it abstract. An abstract class can be extended. An abstract class can be used as a data type. All of these A subclass of a non-abstract superclass can be abstract. 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 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 as declaration of the display method has been provided in two interface. The code will lead to a compilation error due to public modifier while declaring the display method. 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 as declaration of the display method has been provided in two interface. The code will lead to a compilation error due to public modifier while declaring the display method. 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()); }} Compilation fails due to an error on lines 2 Compilation succeed but Runtime Exception Compilation fails due to an error on lines 1 test-name None of these Compilation fails due to an error on lines 2 Compilation succeed but Runtime Exception Compilation fails due to an error on lines 1 test-name None of these ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes In Java, declaring a class abstract is useful To prevent developers from further extending the class. When it doesn't make sense to have objects of that class. When default implementations of some methods are not desirable. When it makes sense to have objects of that class. To force developers to extend the class not to use its capabilities. To prevent developers from further extending the class. When it doesn't make sense to have objects of that class. When default implementations of some methods are not desirable. When it makes sense to have objects of that class. To force developers to extend the class not to use its capabilities. ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes 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); }} Compile with error 10 12 Runtime Exception None of these Compile with error 10 12 Runtime Exception None of these 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 class Dog must implement method doYourJob() from interface Guard. 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 method doYourJob() in interface Guard must be defined abstract. 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 in the declaration of class Dog we must use the keyword extends instead of implements. ANSWER DOWNLOAD EXAMIANS APP
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