JAVA Interfaces and Abstract Classes Which of the following declares an abstract method in an abstract Java class? public abstract void method() {} public abstract method(); public void abstract Method(); public void method() {} public abstract void method(); public abstract void method() {} public abstract method(); public void abstract Method(); public void method() {} public abstract void method(); 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 A null Compilation fails due to an error on line 8 None of these Compilation fails due to an error on line 3 A null Compilation fails due to an error on line 8 None of these 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(); 3 and 4 1 and 2 2 and 3 1 and 3 2 and 4 3 and 4 1 and 2 2 and 3 1 and 3 2 and 4 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 {} 1 and 2 3 and 6 2 and 4 5 and 6 3 and 5 1 and 2 3 and 6 2 and 4 5 and 6 3 and 5 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Determine output of the following code.interface A { }class C { }class D extends C { }class B extends D implements A { }public class Test extends Thread{ public static void main(String[] args){ B b = new B(); if (b instanceof A) System.out.println("b is an instance of A"); if (b instanceof C) System.out.println("b is an instance of C"); }} b is an instance of b is an instance of A followed by b is an instance of Nothing. b is an instance of b is an instance of b is an instance of A followed by b is an instance of Nothing. b is an instance of 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. Class School must be defined abstract. The keywords public and abstract cannot be used together. You must add a return statement in method numberOfStudent(). The method numberOfStudent() in class School must have a body. Class School must be defined abstract. The keywords public and abstract cannot be used together. You must add a return statement in method numberOfStudent(). ANSWER DOWNLOAD EXAMIANS APP
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