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 makes sense to have objects of that class. When it doesn't make 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 makes sense to have objects of that class. When it doesn't make 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 Which of the following is a correct interface? 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(); { }} interface A { void print() { } } 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 1 4 3 2 None of these 1 4 3 2 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes What happens if the following program is compiled and executed?interface MyInterface{ void display();}interface MySubInterface extends MyInterface{ void display();}public class Test implements MySubInterface{ public void display(){ System.out.print("Welcome to Examveda."); } public static void main(String args[]){ Test t = new Test(); t.display(); }} The code will lead to a compilation error as declaration of the display method has been provided in two interface. The code will compile and execute successfully showing the output Welcome to Examians. The code will lead to a compilation error due to public modifier while declaring the display method. The code will lead to a compilation error as the display method is not declared as abstract. None of these The code will lead to a compilation error as declaration of the display method has been provided in two interface. The code will compile and execute successfully showing the output Welcome to Examians. The code will lead to a compilation error due to public modifier while declaring the display method. The code will lead to a compilation error as the display method is not declared as abstract. None of these 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"); }} 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 b is an instance of b is an instance of 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() { } } 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(); } class A { abstract void unfinished(); } ANSWER DOWNLOAD EXAMIANS APP
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