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 it makes sense to have objects of that class. When it doesn't make sense to have objects of that class. When default implementations of some methods are not desirable. To prevent developers from further extending the class. To force developers to extend the class not to use its capabilities. When it makes sense to have objects of that class. When it doesn't make sense to have objects of that class. When default implementations of some methods are not desirable. To prevent developers from further extending the class. ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Given the following piece of code:public class School{ public abstract double numberOfStudent();}which of the following statements is true? The keywords public and abstract cannot be used together. You must add a return statement in method numberOfStudent(). Class School must be defined abstract. The method numberOfStudent() in class School must have a body. The keywords public and abstract cannot be used together. You must add a return statement in method numberOfStudent(). Class School must be defined abstract. The method numberOfStudent() in class School must have a body. 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 3 None of these A null Compilation fails due to an error on line 8 Compilation fails due to an error on line 3 None of these A null Compilation fails due to an error on line 8 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 {} 2 and 4 3 and 6 5 and 6 1 and 2 3 and 5 2 and 4 3 and 6 5 and 6 1 and 2 3 and 5 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which of the following declares an abstract method in an abstract Java class? public abstract method(); public void method() {} public void abstract Method(); public abstract void method(); public abstract void method() {} public abstract method(); public void method() {} public void abstract Method(); public abstract void method(); public abstract void method() {} ANSWER DOWNLOAD EXAMIANS APP
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(); 1 and 3 3 and 4 2 and 4 2 and 3 1 and 2 1 and 3 3 and 4 2 and 4 2 and 3 1 and 2 ANSWER DOWNLOAD EXAMIANS APP
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