JAVA Interfaces and Abstract Classes In Java, declaring a class abstract is useful To prevent developers from further extending the class. To force developers to extend the class not to use its capabilities. 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 prevent developers from further extending the class. To force developers to extend the class not to use its capabilities. 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. 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(); }} Program will compile and execute successfully and prints Compilation error as class can not be declared as abstract. Program compiles but leads to runtime exception. Compilation error occurs as the abstract class TestAbstract contains a non-abstract method. None of these Program will compile and execute successfully and prints Compilation error as class can not be declared as abstract. Program compiles but leads to runtime exception. Compilation error occurs as the abstract class TestAbstract contains a non-abstract method. None of these 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); }} Compilation error due to line 2 Successful run and print 37 Compilation error due to line 1 None of these Runtime error Compilation error due to line 2 Successful run and print 37 Compilation error due to line 1 None of these Runtime error 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(); 1 and 3 2 and 4 3 and 4 1 and 2 2 and 3 1 and 3 2 and 4 3 and 4 1 and 2 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes What is the output for the below code ?interface A{ public void printValue();}1. public class Test{2. public static void main (String[] args){3. A a1 = new A(){4. public void printValue(){5. System.out.println("A");6. }7. };8. a1.printValue();9. }10. } Compilation fails due to an error on line 8 Compilation fails due to an error on line 3 null None of these A Compilation fails due to an error on line 8 Compilation fails due to an error on line 3 null None of these A 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? You must add a return statement in method numberOfStudent(). The method numberOfStudent() in class School must have a body. The keywords public and abstract cannot be used together. Class School must be defined abstract. You must add a return statement in method numberOfStudent(). The method numberOfStudent() in class School must have a body. The keywords public and abstract cannot be used together. Class School must be defined abstract. ANSWER DOWNLOAD EXAMIANS APP
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