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 prevent developers from further extending the class. When it makes 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. When it doesn't make sense to have objects of that class. To prevent developers from further extending the class. When it makes 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. 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 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 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) }} 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 1 and 3 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes What will be the output?1. public interface InfA{2. protected String getName();3. }public class Test implements InfA{ public String getName(){ return "test-name"; } public static void main (String[] args){ Test t = new Test(); System.out.println(t.getName()); }} Compilation succeed but Runtime Exception None of these Compilation fails due to an error on lines 2 test-name Compilation fails due to an error on lines 1 Compilation succeed but Runtime Exception None of these Compilation fails due to an error on lines 2 test-name Compilation fails due to an error on lines 1 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes What will be the output for the below code ?public interface TestInf{ int i =10;}public class Test{ public static void main(String... args){ TestInf.i=12; System.out.println(TestInf.i); }} 12 Compile with error 10 None of these Runtime Exception 12 Compile with error 10 None of these Runtime Exception ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Runnable is a _____ . interface abstract class method class vaiable interface abstract class method class vaiable ANSWER DOWNLOAD EXAMIANS APP
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