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 extended. A subclass of a non-abstract superclass can be abstract. All of these An abstract class can be used as a data type. A subclass can override a concrete method in a superclass to declare it abstract. An abstract class can be extended. A subclass of a non-abstract superclass can be abstract. All of these An abstract class can be used as a data type. 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 3 and 4 1 and 2 2 and 3 4 and 5 1 and 3 3 and 4 1 and 2 2 and 3 4 and 5 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();}} will print Class One method compiles fine but print nothing None of these will print Class Two method Compilation Error will print Class One method compiles fine but print nothing None of these will print Class Two method Compilation Error 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 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. When default implementations of some methods are not desirable. When it makes sense to have objects of that class. To force developers to extend the class not to use its capabilities. To prevent developers from further extending the class. When it doesn't make sense to have objects of that class. When default implementations of some methods are not desirable. When it makes sense to have objects of that class. To force developers to extend the class not to use its capabilities. 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 Compilation error due to line 2 None of these Compilation error due to line 1 Runtime error Successful run and print 37 Compilation error due to line 2 None of these Compilation error due to line 1 Runtime error ANSWER DOWNLOAD EXAMIANS APP
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