Yes, we can declare a class as private but these classes can be only inner or nested classes. We can’t a top-level class as private because it would be completely useless as nothing would have access to it. Example 1 with non inner class: private class Main { public static void main(String[] args) { System.out.println("Inside … Read more
Yes, an abstract class have final methods in java but the final method cannot be abstract. Java interview questions on access modifiers what are access modifiers in java? What are different types of access modifiers in java? What are non access modifiers in java? Can we use abstract and final both with a method? Can … Read more
No, as for an abstract method we have to provide implementation in subclass. To do this abstract method have to be overridden but final methods cannot be overridden. Example abstract class Show{ //abstract final method declaration abstract final void show(); } public class Main extends Show { public static void main(String[] args) { System.out.println("Hello World"); … Read more
Static, final, abstract and synchronized are considered as Non access modifiers in java. static: It is used to represent the class members. It can be used with variable, method, initializer block and nested class. final: It is used to restrict the further modification of instance variables, local variables , methods and classes. abstract: abstract is … Read more
Yes, Static members are also inherited to sub classes in java. package com.w3schools; class A{ static int num = 20; static void method() { System.out.println("Static Method"); } } class B extends A{ } public class Test { public static void main(String args[]){ //Calling inherited static method B.method(); //printing inherited static field. … Read more
Sub class field will hide the Super class field. Hidden super class field in sub class can be accessed using super keyword. Example class Show { int num = 150; } class Display extends Show { int num = 250; public void display(){ System.out.println("num of subclass = " + num); System.out.println("num of super … Read more
No, a class cannot extend itself in java. Example public class Main extends Main { String name = "Jai"; int rollNo = 11; void show(){ System.out.println(name); System.out.println(rollNo); } public static void main(String[] args) { Main object = new Main(); object.show(); } }public class Main extends Main { String name = "Jai"; int rollNo = 11; … Read more
We can restrict a member of a class from inheriting to it’s sub classes by declaring the member as a private. Because, private members are not inherited to sub classes. Example class Student { String name = "Jai"; private int rollNo = 11; } public class Main extends Student { void show(){ System.out.println(name); System.out.println(rollNo); } … Read more
interface cannot have constructor in java, because interface not have any instance member so nothing to construct. Now the question comes how interface can be inherited without constructor because subclass constructor call super class constructor. We have two cases here. First case, interface extends other interface: in this situation there is no issue because as … Read more
interfaces not inherited from object class and there’s no common or root interface which implicitly inherited by all interfaces either. Note: For each public method in Object class, there’s an implicit abstract and public method declared in each interface which doesn’t have direct super interfaces. This standard is defined by JLS (Java Language Specification) as … Read more