JAVA Interfaces and Abstract Classes Which of the following is a correct interface? interface A { void print(); } abstract interface A { print(); } abstract interface A { abstract void print(); { }} interface A { void print() { } } interface A { void print(); } abstract interface A { print(); } abstract interface A { abstract void print(); { }} interface A { void print() { } } 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? 3 2 1 4 None of these 3 2 1 4 None of these ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which of the following class definitions defines a legal abstract class? 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() { } } public class abstract A { abstract void unfinished(); } ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes In Java, declaring a class abstract is useful To prevent developers from further extending the 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 it makes sense to have objects of that class. When default implementations of some methods are not desirable. To prevent developers from further extending the 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 it makes sense to have objects of that class. When default implementations of some methods are not desirable. 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 Which of the following statements regarding abstract classes are true? A subclass can override a concrete method in a superclass to declare it abstract. An abstract class can be used as a data type. All of these An abstract class can be extended. A subclass of a non-abstract superclass can be abstract. A subclass can override a concrete method in a superclass to declare it abstract. An abstract class can be used as a data type. All of these An abstract class can be extended. A subclass of a non-abstract superclass can be abstract. ANSWER DOWNLOAD EXAMIANS APP
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