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 3 1 and 2 2 and 4 1 and 3 3 and 4 2 and 3 1 and 2 2 and 4 1 and 3 3 and 4 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 method numberOfStudent() in class School must have a body. The keywords public and abstract cannot be used together. Class School must be defined abstract. You must add a return statement in method numberOfStudent(). The method numberOfStudent() in class School must have a body. The keywords public and abstract cannot be used together. Class School must be defined abstract. You must add a return statement in method numberOfStudent(). 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 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 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 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 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
JAVA Interfaces and Abstract Classes interface Test{ int p = 10; //line 1 public int q = 20; //line 2 public static int r = 30; //line 3 public static final int s = 40; //line 4}Which of the above line will give compilation error? None of these 2 3 1 4 None of these 2 3 1 4 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which of the following is a correct interface? abstract interface A { abstract void print(); { }} interface A { void print(); } abstract interface A { print(); } interface A { void print() { } } abstract interface A { abstract void print(); { }} interface A { void print(); } abstract interface A { print(); } interface A { void print() { } } 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. } None of these A Compilation fails due to an error on line 8 Compilation fails due to an error on line 3 null None of these A Compilation fails due to an error on line 8 Compilation fails due to an error on line 3 null ANSWER DOWNLOAD EXAMIANS APP
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