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. A subclass can override a concrete method in a superclass to declare it abstract. All of these 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. A subclass can override a concrete method in a superclass to declare it abstract. All of these 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 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 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(); 1 and 3 1 and 2 3 and 4 2 and 3 2 and 4 1 and 3 1 and 2 3 and 4 2 and 3 2 and 4 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? 1 None of these 2 3 4 1 None of these 2 3 4 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes What will happen after compiling this program code?abstract class MyClass{ //line 1 private int a, b; public void call(int a, int b){ this.a = a; this.b = b; System.out.print(a+b); }}public class Test{ public static void main(String args[]){ MyClass m = new MyClass(); //line 2 m.call(12,25); }} Successful run and print 37 Runtime error Compilation error due to line 2 None of these Compilation error due to line 1 Successful run and print 37 Runtime error Compilation error due to line 2 None of these Compilation error due to line 1 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes What will be the output?interface A{public void method();}class One{public void method(){System.out.println("Class One method");}}class Two extends One implements A{public void method(){System.out.println("Class Two method");}}public class Test extends Two{public static void main(String[] args){A a = new Two();a.method();}} compiles fine but print nothing will print Class Two method will print Class One method Compilation Error None of these compiles fine but print nothing will print Class Two method will print Class One method Compilation Error None of these ANSWER DOWNLOAD EXAMIANS APP
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