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? 2 None of these 3 4 1 2 None of these 3 4 1 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which of the following class definitions defines a legal abstract class? class A { abstract void unfinished() { } } abstract class A { abstract void unfinished(); } class A { abstract void unfinished(); } public class abstract A { abstract void unfinished(); } class A { abstract void unfinished() { } } abstract class A { abstract void unfinished(); } class A { abstract void unfinished(); } public class abstract A { abstract void unfinished(); } 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 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. This code will compile without any errors. 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 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 Nothing. 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) }} 1 and 3 2 and 3 3 and 4 1 and 2 4 and 5 1 and 3 2 and 3 3 and 4 1 and 2 4 and 5 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes In Java, declaring a class abstract is useful When it doesn't make sense to have objects of that class. To force developers to extend the class not to use its capabilities. When default implementations of some methods are not desirable. To prevent developers from further extending the class. When it makes sense to have objects of that class. When it doesn't make sense to have objects of that class. To force developers to extend the class not to use its capabilities. When default implementations of some methods are not desirable. To prevent developers from further extending the class. When it makes sense to have objects of that class. ANSWER DOWNLOAD EXAMIANS APP
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