Basically, the protected keyword is an access modifier for method and variable of a class. When a method or a variable is marked as protected, it can be accessed from: Within the enclosing class. Other classes in the same package as the enclosing class.
Why would you use protected in Java?
Protecting a constructor prevents the users from creating the instance of the class, outside the package. During overriding, when a variable or method is protected, it can be overridden to other subclass using either a public or protected modifier only. Outer class and interface cannot be protected.
What is the use of protected access specifier in Java?
Protected Access Modifier
It is a keyword. This access modifier is used to access the methods or data members of a class within the same package as well as outside the package but only through inheritance. The protected access modifier has more accessibility than private and defaults access modifiers.
What is the scope of protected in Java?
When a variable, method or constructor that are declared protected in a superclass can be accessed only by the subclasses in other package or any class within the package of the protected members’ class.
Can we use protected for a class in Java?
You can declare nested and inner classes as protected or private, though. > Since there’s no such concept as ‘subpackage’ or ‘package-inheritance’ in Java, declaring class protected or package-private would be the same thing.
What is protected in Java?
In Java, protected means that the member can be accessed by any class in the same package and by subclasses even if they are in another packages.
What is protected method?
A protected method is like a private method in that it can only be invoked from within the implementation of a class or its subclasses. It differs from a private method in that it may be explicitly invoked on any instance of the class, and it is not restricted to implicit invocation on self .
What is difference between default and protected in Java?
The protected specifier allows access by all subclasses of the class in question, whatever package they reside in, as well as to other code in the same package. The default specifier allows access by other code in the same package, but not by code that is in subclasses residing in different packages.
Why is String immutable in Java?
The String is immutable in Java because of the security, synchronization and concurrency, caching, and class loading. The reason of making string final is to destroy the immutability and to not allow others to extend it. The String objects are cached in the String pool, and it makes the String immutable.
What is Polymorphism in Java?
Polymorphism in Java is the ability of an object to take many forms. To simply put, polymorphism in java allows us to perform the same action in many different ways. … Polymorphism is a feature of the object-oriented programming language, Java, which allows a single task to be performed in different ways.
What is array in Java?
An array in Java is a set of variables referenced by using a single variable name combined with an index number. Each item of an array is an element. All the elements in an array must be of the same type. … An int array can contain int values, for example, and a String array can contain strings.
Can constructor be private?
Yes. Class can have private constructor. Even abstract class can have private constructor. By making constructor private, we prevent the class from being instantiated as well as subclassing of that class.
Can we 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 call method from constructor?
You shouldn’t: calling instance method in constructor is dangerous because the object is not yet fully initialized (this applies mainly to methods than can be overridden). Also complex processing in constructor is known to have a negative impact on testability.