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(); 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 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? None of these 2 4 3 1 None of these 2 4 3 1 ANSWER DOWNLOAD EXAMIANS APP
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. To force developers to extend the class not to use its capabilities. When default implementations of some methods are not desirable. When it makes sense to have objects of that class. When it doesn't make 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 makes sense to have objects of that class. 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 will print Class One method compiles fine but print nothing None of these Compilation Error will print Class Two method will print Class One method compiles fine but print nothing ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes What will be the output when the following program is compiled and executed?abstract class TestAbstract{ String my_name; String myName(){ my_name = "Examveda"; return my_name; } abstract void display();}public class Test extends TestAbstract{ void display(){ String n = myName(); System.out.print("My name is "+ n); } public static void main(String args[]){ Test t = new Test(); t.display(); }} Compilation error as class can not be declared as abstract. None of these Program will compile and execute successfully and prints Program compiles but leads to runtime exception. Compilation error occurs as the abstract class TestAbstract contains a non-abstract method. Compilation error as class can not be declared as abstract. None of these Program will compile and execute successfully and prints Program compiles but leads to runtime exception. Compilation error occurs as the abstract class TestAbstract contains a non-abstract method. ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which of the following class definitions defines a legal abstract class? class A { abstract void unfinished() { } } class A { abstract void unfinished(); } abstract class A { abstract void unfinished(); } public class abstract A { abstract void unfinished(); } class A { abstract void unfinished() { } } class A { abstract void unfinished(); } abstract class A { abstract void unfinished(); } public class abstract A { abstract void unfinished(); } ANSWER DOWNLOAD EXAMIANS APP
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