JAVA Interfaces and Abstract Classes In Java, declaring a class abstract is useful When default implementations of some methods are not desirable. When it doesn't make sense to have objects of that class. When it makes sense to have objects of that class. To prevent developers from further extending the 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. When it makes sense to have objects of that class. To prevent developers from further extending the class. To force developers to extend the class not to use its capabilities. 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()); }} None of these Compilation succeed but Runtime Exception Compilation fails due to an error on lines 1 test-name Compilation fails due to an error on lines 2 None of these Compilation succeed but Runtime Exception Compilation fails due to an error on lines 1 test-name Compilation fails due to an error on lines 2 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which of the following is a correct interface? interface A { void print() { } } 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(); { }} ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Given the following piece of code:public class School{ public abstract double numberOfStudent();}which of the following statements is true? The keywords public and abstract cannot be used together. You must add a return statement in method numberOfStudent(). Class School must be defined abstract. The method numberOfStudent() in class School must have a body. The keywords public and abstract cannot be used together. You must add a return statement in method numberOfStudent(). Class School must be defined abstract. The method numberOfStudent() in class School must have a body. 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); }} 10 Runtime Exception Compile with error None of these 12 10 Runtime Exception Compile with error None of these 12 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(); 2 and 3 3 and 4 1 and 2 1 and 3 2 and 4 2 and 3 3 and 4 1 and 2 1 and 3 2 and 4 ANSWER DOWNLOAD EXAMIANS APP
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