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(); 2 and 4 3 and 4 1 and 2 1 and 3 2 and 3 2 and 4 3 and 4 1 and 2 1 and 3 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes In Java, declaring a class abstract is useful 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 it makes sense to have objects of that class. When default implementations of some methods are not desirable. 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 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 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();}} None of these Compilation Error will print Class Two method compiles fine but print nothing will print Class One method None of these Compilation Error will print Class Two method compiles fine but print nothing will print Class One method ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which of the following declares an abstract method in an abstract Java class? public abstract void method(); public void method() {} public abstract void method() {} public abstract method(); public void abstract Method(); public abstract void method(); public void method() {} public abstract void method() {} public abstract method(); public void abstract Method(); 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 Which of the following class definitions defines a legal abstract class? 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(); } class A { abstract void unfinished() { } } abstract class A { abstract void unfinished(); } class A { abstract void unfinished(); } ANSWER DOWNLOAD EXAMIANS APP
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