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. To prevent developers from further extending the class. When it makes sense to have objects of that class. When default implementations of some methods are not desirable. When it doesn't make 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 makes sense to have objects of that class. When default implementations of some methods are not desirable. When it doesn't make sense to have objects of that class. 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();}} None of these compiles fine but print nothing Compilation Error will print Class Two method will print Class One method None of these compiles fine but print nothing Compilation Error will print Class Two method will print Class One method 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 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. 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. ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which of the following statements regarding abstract classes are true? An abstract class can be used as a data type. A subclass can override a concrete method in a superclass to declare it abstract. All of these An abstract class can be extended. A subclass of a non-abstract superclass can be abstract. An abstract class can be used as a data type. A subclass can override a concrete method in a superclass to declare it abstract. All of these An abstract class can be extended. A subclass of a non-abstract superclass can be abstract. ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes interface Base{ boolean m1 (); byte m2(short s);}which two code fragments will compile?1. interface Base2 implements Base {}2. abstract class Class2 extends Base { public boolean m1(){ return true; }}3. abstract class Class2 implements Base {}4. abstract class Class2 implements Base { public boolean m1(){ return (7 > 4); }}5. abstract class Class2 implements Base { protected boolean m1(){ return (5 > 7) }} 2 and 3 3 and 4 1 and 2 1 and 3 4 and 5 2 and 3 3 and 4 1 and 2 1 and 3 4 and 5 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. } A Compilation fails due to an error on line 8 null Compilation fails due to an error on line 3 None of these A Compilation fails due to an error on line 8 null Compilation fails due to an error on line 3 None of these ANSWER DOWNLOAD EXAMIANS APP
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