Can we have 2 main methods in Java?

Inhaltsverzeichnis:

1. Can we have 2 main methods in Java?
2. Can we override static method?
3. Why we can not override static method?
4. Can we override main method?
5. Why we Cannot override final method?
6. Can final method override?
7. Can we inherit a final method?
8. Can final method be overloaded?
9. Can a final class be abstract?
10. Can we override private method in Java?
11. Can we extend final method in Java?
12. Can we inherit static method in Java?
13. Can we extend multiple classes in Java?
14. Can we extend abstract class in Java?
15. Can abstract class have constructor?
16. Can one abstract class extend another?
17. Can abstract class have method body?
18. Can we override constructor?
19. What happens if an abstract method is not defined?
20. Can we declare abstract class as static?
21. Can we make constructors static?
22. Can we declare an interface as final?
23. Is it possible to inherit from multiple abstract classes in Java?
24. How can we use two classes in Java?
25. What is not type of inheritance?
26. Why we Cannot extend two classes in Java?

Can we have 2 main methods in Java?

The only way to have two main methods is by having two different classes each with one main method. The name of the class you use to invoke the JVM (e.g. java Class1, java Class2) determines which main method is called.

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'.

Why we can not 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 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. ... Therefore, it is not possible to override the main method in java.

Why we Cannot override final method?

The reason for not overriding static method is that Static methods are treated as global by the JVM so there are not bound to an object instance at all. Similarly final methods cant be overriddent because when you say a method as final then it mean you are saying to the JVM that this method cannot be overridden.

Can final method override?

Can We Override a Final Method? No, the Methods that are declared as final cannot be Overridden or hidden. ... Methods are declared final in java to prevent subclasses from Overriding them and changing their behavior, the reason this works is discussed at the end of this article.

Can we inherit a final method?

No, we cannot override a final method in Java. The final modifier for finalizing the implementations of classes, methods, and variables. We can declare a method as final, once you declare a method final it cannot be overridden.

Can final method be overloaded?

private and final methods can be overloaded but they cannot be overridden. It means a class can have more than one private/final methods of same name but a child class cannot override the private/final methods of their base class.

Can a final class be abstract?

because as soon as you declare an abstract method in a Java class, the class automatically becomes an abstract class and you cannot make an abstract class final in Java as discussed before, hence it's not possible to have an abstract method in a final class in Java.

Can we override private method in Java?

No, we cannot override private or static methods in Java. Private methods in Java are not visible to any other class which limits their scope to the class in which they are declared.

Can we extend final method in Java?

In Java final is the access modifier which can be used with a filed class and a method. When a method if final it cannot be overridden. When a variable is final its value cannot be modified further. When a class is finale it cannot be extended.

Can we inherit static method in Java?

Static methods are inherited in Java but they don't take part in polymorphism. If we attempt to override the static methods they will just hide the superclass static methods instead of overriding them.

Can we extend multiple classes in Java?

A class can extend only one class, but implement many interfaces. An interface can extend another interface, in a similar way as a class can extend another class.

Can we extend abstract class in Java?

Abstract classes are similar to interfaces. You cannot instantiate them, and they may contain a mix of methods declared with or without an implementation. ... In addition, you can extend only one class, whether or not it is abstract, whereas you can implement any number of interfaces.

Can abstract class have constructor?

The constructor inside the abstract class can only be called during constructor chaining i.e. when we create an instance of sub-classes. This is also one of the reasons abstract class can have a constructor.

Can one abstract class extend another?

Abstract classes can implement one or more interfaces and can extend one abstract class at most. ... Abstract classes can extend other at most one abstract or concrete class and implement several interfaces. Any class that does not implement all the abstract methods of it's super class has to be an abstract class itself.

Can abstract class have method body?

Abstract methods cannot have body. Abstract class can have static fields and static method, like other classes. An abstract class cannot be declared as final.

Can we override constructor?

Constructor looks like method but it is not. It does not have a return type and its name is same as the class name. But, a constructor cannot be overridden. If you try to write a super class's constructor in the sub class compiler treats it as a method and expects a return type and generates a compile time error.

What happens if an abstract method is not defined?

Abstract method basically says, that there is no implementation of the method and it needs to be implemented in a subclass. However if you had an abstract method in a non-abstract class, you could instantiate the class and get an object, that would have an unimplemented method, which you would be unable to call.

Can we declare abstract class as static?

Declaring abstract method static If you declare a method in a class abstract to use it, you must override this method in the subclass. But, overriding is not possible with static methods. Therefore, an abstract method cannot be static.

Can we make constructors static?

No, we cannot define a static constructor in Java, If we are trying to define a constructor with the static keyword a compile-time error will occur. In general, static means class level. A constructor will be used to assign initial values for the instance variables.

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”.

Is it possible to inherit from multiple abstract classes in Java?

Basically, the rule says that you can inherit from (extend) as many classes as you want, but if you do, only one of those classes can contain concrete (implemented) methods. ... A class can extend at most one abstract class, but may implement many interfaces. That is, Java supports a limited form of multiple inheritance.

How can we use two classes in Java?

How the compiler behave with Multiple non-nested classes. In the below example, the java program contains two classes, one class name is Computer and another is Laptop. Both classes have their own constructors and a method. In the main method, we can create an object of two classes and call their methods.

What is not type of inheritance?

Explanation: All classes in java are inherited from Object class. Interfaces are not inherited from Object Class. ... Static members are not inherited to subclass.

Why we Cannot extend two classes in Java?

Java does not support multiple inheritance, that's why you can't extend a class from two different classes at the same time. ... Rather, use a single class to extend from, and use interfaces to include additional functionality.