- Can abstract class have constructors?
- Can abstract class have private methods?
- Can a class be static?
- Can abstract class have static and final methods?
- Why we Cannot override static method?
- Can an interface have static methods?
- Can we declare an interface as final?
- Can we declare abstract class as final?
- Can we override final method?
- Can we override static method?
- Can abstract class have static?
- Can we inherit abstract class?
- Can a constructor be final?
- Why is main method static?
- Can we declare the static variables and methods in an abstract class?
- What is the difference between static and final?
- Can we override main method?
- Can a variable be static and final?
Can abstract class have constructors?
Abstract classes can have constructors.
Yes, when we define a class to be an Abstract Class it cannot be instantiated but that does not mean an Abstract class cannot have a constructor.
Each abstract class must have a concrete subclass which will implement the abstract methods of that abstract class..
Can abstract class have private methods?
If a method of a class is private, you cannot access it outside the current class, not even from the child classes of it. But, incase of an abstract method, you cannot use it from the same class, you need to override it from subclass and use. Therefore, the abstract method cannot be private.
Can a class be static?
So, Yes, you can declare a class static in Java, provided the class is inside a top-level class. Such clauses are also known as nested classes and they can be declared static, but if you are thinking to make a top-level class static in Java, then it’s not allowed.
Can abstract class have static and final methods?
Yes, it can. But the final method cannot be abstract itself (other non-final methods in the same class can be).
Why we Cannot override static method?
Static methods cannot be overridden because they are not dispatched on the object instance at runtime. The compiler decides which method gets called. Static methods can be overloaded (meaning that you can have the same method name for several methods as long as they have different parameter types).
Can an interface have static methods?
You can’t define static methods in an interface because static methods belongs to a class not to an instance of class, and interfaces are not Classes. Read more here. In this case what you have is two classes with 2 distinct static methods called methodX().
Can we declare an interface as final?
If you make an interface final, you cannot implement its methods which defies the very purpose of the interfaces. Therefore, you cannot make an interface final in Java. Still if you try to do so, a compile time exception is generated saying “illegal combination of modifiers − interface and final”.
Can we declare abstract class as final?
In short, an abstract class cannot be final in Java, using both abstract and final modifier with a class is illegal in Java. … An abstract method must be overridden to be useful and called but when you make the abstract method final it cannot be overridden in Java, hence there would be no way to use that method.
Can we override final method?
You use the final keyword in a method declaration to indicate that the method cannot be overridden by subclasses.
Can we override static method?
Can we Override static methods in java? We can declare static methods with the same signature in the subclass, but it is not considered overriding as there won’t be any run-time polymorphism. Hence the answer is ‘No’.
Can abstract class have static?
Can an abstract class have static methods? Yes, abstract class can have Static Methods. The reason for this is Static methods do not work on the instance of the class, they are directly associated with the class itself.
Can we inherit abstract class?
An abstract class defines the identity of a class. An interface can inherit multiple interfaces but cannot inherit a class. An abstract class can inherit a class and multiple interfaces. … An abstract class can declare constructors and destructors.
Can a constructor be final?
No, a constructor can’t be made final. A final method cannot be overridden by any subclasses. … But, in inheritance sub class inherits the members of a super class except constructors. In other words, constructors cannot be inherited in Java therefore, there is no need to write final before constructors.
Why is main method static?
Why the main () method in Java is always static? Java main() method is always static, so that compiler can call it without the creation of an object or before the creation of an object of the class. In any Java program, the main() method is the starting point from where compiler starts program execution.
Can we declare the static variables and methods in an abstract class?
Yes, of course you can define the static method in abstract class. you can call that static method by using abstract class,or by using child class who extends the abstract class. Also you can able to call static method through child class instance/object.
What is the difference between static and final?
static means there is only one copy of the variable in memory shared by all instances of the class. The final keyword just means the value can’t be changed. Without final , any object can change the value of the variable.
Can we override main method?
No, we cannot override main method of java because a static method cannot be overridden. The static method in java is associated with class whereas the non-static method is associated with an object.
Can a variable be static and final?
Class variables also known as static variables are declared with the static keyword in a class, but outside a method, constructor or a block. Static variables are stored in the static memory, mostly declared as final and used as either public or private constants. …