Yes, SuperClass protected methods can be overridden by subclasses. If a SuperClass method is protected, the overridden method in the subclass can be protected or not exposed (not default or private).
Can u access protected members in override methods?
If a method is overridden, the overridden method (i.e., declared in a subclass) must not be more restrictive. According to the previous point, if assigned to a protected method or variable, that method or variable can be overridden in a subclass using only public or protected access modifiers.
Can a public method be overridden?
If a method cannot be inherited, it cannot be overridden. Subclasses in the same package as the instance’s superclass may override superclass methods that are not declared private or final. Subclasses in another package can only override non-final methods that are declared public or protected.
Can I call protected method?
If a class is not final, you can use an anonymous class to call its protected method: new ClassWithProtectedMethod() >.
Can protected method be inherited?
Protected means that access to the method is restricted to the same package or inheritance. Thus, the answer is, yes, protected methods can be overridden by subclasses of any package. In contrast, a package (default) scope method is not visible to subclasses in another package.
Can we extend protected class?
class is defined protected —> They cannot be extended from an external package (not shown). Also, if it cannot be extended, it is pointless to leave it protected. This is because it will be the default access that is allowed.
Can we override non abstract method in Java?
Is it good practice in Java to disable non-abstract methods?” Yes, it is.
Can constructor be protected in Java?
Use the constructor to access the allowed specifications/modifiers Public, protected, and private modifiers are allowed in the constructor. You can use Java’s private constructor while creating a Singleton class. The purpose of Singleton is to control object creation and limit the number of objects to only one.
Can protected members be inherited in Java?
A subclass inherits all the public and protected members of its parent, regardless of what package the subclass is in.
Can we create immutable class in Java?
An immutable class in Java means that once an object is created, its contents cannot be modified. In Java, all wrapper classes (Integer, Boolean, Byte, Short, etc.) and String classes are not possible. You can also create your own immutable classes.
Can object access protected members?
Protected members of a class are similar to private members because they cannot be accessed from outside the class. However, private members cannot, but can be accessed in derived or child classes.
Can we overload constructor in Java?
Yes! Java supports constructor overloading. Constructor overloading creates multiple constructors with the same name but different parameter types or without different parameters.
Can we overload abstract method in Java?
Subclasses must override all abstract methods of abstract classes. However, if the subclass is declared abstract, it is not required to override the abstract methods.
Can we declare abstract method as private?
If a class method is private, it cannot be accessed outside of the current class, not from a child class. However, if the abstract method is available, it cannot be used from the same class. It must be used and used from a subclass. Therefore, abstract methods cannot be private.
Can we declare static methods as private?
Yes, you can use private methods or private static methods for Java 9 interfaces.
Can we have constructor in abstract class?
Like any other class in Java, an abstract class can have a constructor, even if it is called only from a concrete subclass.
Can we inherit abstract class?
Abstract classes cannot inherit by construction. It can contain a constructor or destructor. Can implement functions using non-abstract methods. Cannot support multiple inheritance.
Can a class be declared as synchronized?
Synchronized keywords can only be used in method declarations and as synchronization blocks. When used in a method declaration, this is equivalent to adding a synchronized block around the method content and synchronizing this. Nothing prevents you from synchronizing all methods of a class.
Can outer class default?
Java inner classes are defined within the body of another class. Java inner classes can be declared with private, public, protected, or default access, while outer classes can only have public or default access.
Can abstract class have protected constructor?
Constructors of abstract types can only be invoked by derived types. Abstract types with public constructors are incorrectly designed because public constructors create instances of the type and cannot create instances of abstract types.
Can we use void with constructor?
Note that the constructor name must match the class name and must not have a return type (e.g. void). Also note that the constructor is called when the object is created.
Can we declare a class as protected?
No, top-level classes cannot be declared private or protected. It can be either public or default (no qualifier). If there is no qualifier, there should be default access.
Can a child class access private?
Access to inherited private fields. Inheritance means that objects in a child class automatically contain the object fields and methods defined in the parent class. However, if the inherited fields are private, as it should be, the child class cannot directly access the inherited fields using dot notation.
How many protected members are there in base class?
If a class is privately derived from a base class, all protected members of the base class become private members of the derived class. Class A contains one protected data member, integer i. Class Since B is derived from A, members of B have access to the protected member of A.
Can subclasses access private variables?
Can I access private variables from a superclass using the super keyword in a subclass? No. Private variables can only be accessed by the class members to which they belong. Private variables can only be accessed by the class members to which they belong.
Is Double immutable in Java?
For example, Java, String, Integer, and Double are immutable classes, while StringBuilder, Stack, and Java Array are variable.
Can we break immutable class in Java?
More detailed answer: yes serialization may break immutability. It looks good. It is immutable (start and end cannot be changed after initialization), elegant, small, thread-safe, etc. Must remember that serialization is another way to create objects (and does not use a constructor).
What is protected vs private?
Private: the type or member can only be accessed by code of the same class or structure. Protected: the type or member can only be accessed by code of the same class or a class derived from that class.
How do I access protected variables?
Protected Access Modifier – Protected Variables, methods, and constructors declared as protected in a superclass are accessible only in subclasses of other packages or any class in a package of protected member classes. Protected access modifiers cannot be applied to classes and interfaces.
Can we have 2 main methods in Java?
From the above program it can be said that Java can have multiple primary methods but with the concept of overload. String [] arg.
Can we override constructor?
A constructor looks like a method, but it is not. It has no return type and its name is the same as the class name. However, constructors cannot be overridden. Attempting to create a superclass constructor in a subclass compiler will treat it as a method, expect a return type, and generate a compile-time error.
Can constructor have return type?
No, constructors do not have a return type in Java. A constructor looks like a method, but it is not. There is no return type and its name is the same as the class name. It is primarily used to instantiate an instance variable of a class.
Can constructor synchronized Java?
Constructor cannot be synchronized – it is a syntax error to use synchronized keywords with a constructor. Constructor synchronization makes no sense. Because only the thread creating the object should have access to it during construction.
Can we change return type in overloading?
No, you cannot overload a method based on different return types, but in Java we have the same argument types and numbers.
CAN interface have two methods?
If two interfaces contain methods with the same signature and different return types, it is not possible to implement both interfaces simultaneously. According to the JLS (§8.4. 2), methods with the same signature are not allowed in this case.
Can destructor be private?
Destructors with access modifiers as private are known as private destructors. Whenever you want to prevent the destruction of an object, you can make the Destructor private.
How can we make a class singleton?
To create a Singleton class, you need a class, a private constructor, and a static member of the static factory method. Static member: gets memory only once for the static. Private constructor: prevents instantiation of the Singleton class from outside the class.
Can interface be declared as private?
Therefore, interface members cannot be private. Attempting to declare a member of an interface private will generate a compile-time error.
Can we declare abstract static method?
Declaring Abstract Methods Static If a method is used in a class abstract, this method must be overridden in a subclass. However, overriding a static method is not possible. Therefore, abstract methods cannot be static.
Can we override private static and final method?
Java private or static methods cannot be overridden.
Are protected methods final?
1) Private methods are final. 2) Protected members are accessible within the package and to inherited classes outside the package. 3) Protected methods are final.
Can an abstract class implement an interface?
A Java Abstract class can implement an interface without providing an implementation of the interface method. The Java Abstract class can be used to provide common method implementations for all subclasses or to provide default implementations.
Can abstract class be instantiated?
Abstract classes cannot be instantiated, but can be subclassed. When an abstract class is subclassed, the subclass typically provides implementations of all abstract methods of the parent class. However, if this is not the case, the subclass must also be declared abstract.
Can we create object of interface?
As with abstract classes, you cannot create objects using interfaces (in the above example, you cannot create an “animal” object in mymainclass) Interface methods have no body – the body is provided by the “implementing” class The body is provided by the “implementation” class. The interface implementation must have a body. An implementation of an interface must override all its methods.
Can abstract class extend another class?
Concrete class is the conventional term used to distinguish a class from an abstract class. Also, an abstract class cannot be instantiated, only extended. An abstract class can extend another abstract class. Concrete subclasses must also ensure that all abstract methods are implemented.
Can interface be inherited?
An interface can inherit from one or more interfaces. Derived interfaces inherit their members from the base interface. A class implementing a derived interface must implement all members of the derived interface, including all members of the base interface of the derived interface.
Can object class be a base class?
The object class is the base class for all classes. Net Framework.
Can we declare constructor as private?
Yes, you can declare a constructor as private. If you declare the constructor as private, you cannot create objects of the class. This private constructor can be used in the Singleton Design Pattern.
Why main () method is declared as static?
The Java Main () method is always static, so the compiler can call it without creating an object or before creating an object of class. In a Java program, the Main () method is the starting point from which the compiler begins program execution. Therefore, the compiler must call the Main () method.
Can we use static and synchronized together?
Static methods can be synchronized. However, there is one lock per class. Java class when the corresponding Java is loaded.
Can Java inner class be private?
Unlike classes, inner classes are private, and if an inner class is declared private, it cannot be accessed by objects outside the class. The following is a program that creates and accesses an inner class.
Why constructor have no return type?
Thus, the reason the constructor does not return a value is because it is not called directly by the code, but by the run-time memory allocation and object initialization code. Its return value (if there is one when actually compiled into machine code) is opaque to the user. Therefore, it cannot be specified.