JAVA Interfaces and Abstract Classes Which of the following class definitions defines a legal abstract class? public class abstract A { abstract void unfinished(); } abstract class A { abstract void unfinished(); } class A { abstract void unfinished(); } class A { abstract void unfinished() { } } public class abstract A { abstract void unfinished(); } abstract class A { abstract void unfinished(); } class A { abstract void unfinished(); } class A { abstract void unfinished() { } } 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"); }} Nothing. b is an instance of A followed by b is an instance of b is an instance of b is an instance of Nothing. b is an instance of A followed by b is an instance of b is an instance of b is an instance of ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which of the following declares an abstract method in an abstract Java class? public abstract void method() {} public void method() {} public void abstract Method(); public abstract void method(); public abstract method(); public abstract void method() {} public void method() {} public void abstract Method(); public abstract void method(); public abstract method(); 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. All of these A subclass can override a concrete method in a superclass to declare it abstract. A subclass of a non-abstract superclass can be abstract. An abstract class can be extended. An abstract class can be used as a data type. All of these A subclass can override a concrete method in a superclass to declare it abstract. A subclass of a non-abstract superclass can be abstract. An abstract class can be extended. ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which of the following is a correct interface? interface A { void print() { } } abstract interface A { abstract void print(); { }} abstract interface A { print(); } interface A { void print(); } interface A { void print() { } } abstract interface A { abstract void print(); { }} abstract interface A { print(); } interface A { void print(); } 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 in the declaration of class Dog we must use the keyword extends instead of implements. This code will not compile, because class Dog must implement method doYourJob() from interface Guard. 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 in the declaration of class Dog we must use the keyword extends instead of implements. This code will not compile, because class Dog must implement method doYourJob() from interface Guard. This code will not compile, because method doYourJob() in interface Guard must be defined abstract. This code will compile without any errors. ANSWER DOWNLOAD EXAMIANS APP