Class cannot have data as a protected member. B. Structures can have functions as members.
Can class users access private data members?
Private: Class members declared as private can only be accessed by member functions within the class. Direct access by objects or functions outside the class is not permitted. Only member or friend functions can access private data members of the class.
Are protected members of Java class are?
Protected Access Modifiers – Protected Variables, methods, and constructors declared as protected in a superclass can only be accessed by subclasses of other packages or any class in a package of protected member classes. Protected access modifiers cannot be applied to classes and interfaces.
What are protected data members?
Public vs. Protected Differences
| Public | Protected. |
|---|---|
| Public data members and member functions can be accessed by other classes. | Class members declared protected cannot be accessed outside of the class, but can be accessed by any subclass (derived class) of that class. |
How many protected members are there in base class?
If a class is privately derived from a base class, all protected base class members become private members of the derived class. Class A contains one protected data member, integer i. Class B contains one protected data member, integer i. Class B contains one protected data member, integer i. Class B is a private member of class A. Since B is derived from A, members of B have access to the protected members of A.
Who can access protected members in a class?
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.
How many data members can a class contain?
This leads to undefined use of new data types. 5. How many data members does a class contain? Explanation: Any class can have as many data members as needed.
Can we inherit protected class?
With protected inheritance, the protected members of the base class of a derived class are protected in the derived class. With private inheritance, public and protected members of the base class become private in the derived class.
Can we have protected constructor in Java?
Public, protected, and private modifiers are allowed in the constructor. While creating a Singleton class, you can use Java’s private constructor.
What is difference between private and protected?
Private ones are visible only in the class itself. Protected ones appear in the class itself and in subclasses.
Which of the following is false about protected class members?
13. Which of the following is false about protected class members? Explanation: Protected class members are not accessible by name mangling.
Can private members of a base class are inheritable?
Yes, private members of the base class are inherited by derived classes. However, objects of the derived class cannot use or modify it.
Which members of a class Cannot be inherited?
Explanation: Private members of a class cannot be inherited. They can only be accessed by members of their own class.
What is difference between public/private and protected in Java?
You can access public members from child classes of the same package. Private members cannot be accessed from child classes of the same package. Protected members can be accessed from child classes of the same package. Package members can be accessed from child classes of the same package.
What are protected members in Java?
Definition and Usage. Protected keywords are access modifiers used for attributes, methods, and constructors that are accessible in the same package and subclasses.
What types are allowed to be used for data members of a class?
Data members may be of any type, including already defined classes, pointers to objects of any type, or references to objects of any type. Data members may be private or public, but are usually kept private and may have their values changed only at the discretion of the class function member.
What is a public data member?
All variables of a class are known as “data members of the class,” and variables declared in the public section of the class are known as “public data members of the class.” Public data members are accessible via object names outside of the class.
Can we access protected member outside the package?
Protected Access Modifier can be accessed within the package. However, they are accessible outside the package only by inheritance. Protected assignments cannot be made to protected outer classes and interfaces. If a constructor is protected, no instance of that class can be created outside of the package.
Can a constructor be private?
Yes, you can declare the 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.
Can abstract methods have constructor?
Like other classes in Java, an abstract class can have a constructor even if it is called only from a concrete subclass.
Is protected the same as public?
The difference between public and protected is that public can be accessed by external classes, but protected cannot be accessed by external classes.
Are classes public by default in Java?
By default, class visibility is package private. That is, it is visible only to classes in the same package.
What is inheritance in OOP?
OOP = when a class is derived from another class. The child class inherits all public and protected properties and methods from the parent class. Additionally, it can have its own properties and methods. Inherited classes are defined using the extends keyword.
Why we use public private and protected?
If a class member is declared public, it can be accessed from anywhere. If a class member is declared protected, it can only be accessed within the class itself, by inheriting from a child class. If a class member is declared as private, it can only be accessed from the class that defines the member.
Which of the following statement is true about protected components of a class?
The above statement is true. Protected members are allowed in the same package and can be accessed in other packages. However, members with default access specifiers cannot be inherited by subclasses of other packages.
Which statement is true with regard to the private and protected members of a class?
D. A protected member of a class can be inherited by a subclass and become a private member of the subclass. Explanation : Private members of a class cannot be inherited by subclasses.
Can a class have more than one parent class?
Multiple inheritance is a feature of the object-oriented concept that allows a class to inherit properties of multiple parent classes. This problem occurs when a method has the same signature in both a superclass and a subclass.
Are private variables visible to subclasses?
Private fields in the superclass may be accessible from the subclass. For example, when both classes are members of the same class. However, private fields are not inherited by subclasses. InnerA accessibility description.
Is polymorphism possible in C?
Description: It is possible to implement polymorphism in C without class support. You can use a structure and then declare a pointer pointing to some function. In this way, you simulate a function that looks like a member function, but is not exactly a member function.
Can virtual functions private?
Since C++ has access controls but no visibility controls, virtual functions can be private. As mentioned earlier, virtual functions can be overridden by derived classes, but in all circumstances they are called only within the base class.
Can we have a virtual constructor in the class?
In C++, constructors cannot be virtual. When the constructor of a class is executed, there is no virtual table in memory, which means that the virtual pointer has not yet been defined. Therefore, the constructor must always be non-virtual. However, virtual destructors are possible.
Can constructor be overloaded in derived class?
Constructors cannot be defined in derived classes and therefore cannot be overloaded even in derived classes.
Can we use protected for a class in Java?
No, top-level classes cannot be declared as private or protected. Either public or default (no qualifier).
How many protected members are there in base class?
If a class is privately derived from a base class, all protected base class members become private members of the derived class. Class A contains one protected data member, integer i. Class B contains one protected data member, integer i. Class B contains one protected data member, integer i. Class B is a private member of class A. Since B is derived from A, members of B have access to the protected members of A.
Is protected package private?
The private modifier specifies that the member can only be accessed by its own class. The protected modifier specifies that the member is accessible only within its own package (as with package-private) and can also be accessed by subclasses of that class in other packages.
What is the difference between public/private and protected data members?
public – allows access to the member from outside the class. private – the member cannot be accessed (or displayed) from outside the class. protected – members cannot be accessed from outside the class, but can be accessed in an inherited class.
Can we inherit protected class?
With protected inheritance, the protected members of the base class of a derived class are protected in the derived class. With private inheritance, public and protected members of the base class become private in the derived class.
Can subclasses access protected variables?
Protected Access Modifiers – Protected Variables, methods, and constructors that are declared protected in a superclass can only be accessed by subclasses of other packages or by any class in the package of protected member classes.
How do you access data members of a class?
Accessing Data Members and Member Functions: Data members and member functions of a class can be accessed using the dot (‘.’) operator. For example, if an object is named obj and you want to access a member function named printName(), you must write obj.
Why are data members private in C++?
Private: Class members declared as private can only be accessed by member functions within the class. Direct access by objects or functions outside the class is not permitted. Only member or friend functions can access private data members of the class.
Which type of data members are accessible outside a class?
Public members form an interface to the class and can be accessed from outside the class. Instances of a class data type are called objects and can contain member variables, constants, member functions, and overloaded operators defined by the programmer.
What types are allowed to be used for data members of a class?
Data members may be of any type, including already defined classes, pointers to objects of any type, or references to objects of any type. Data members may be private or public, but are usually kept private and may have their values changed only at the discretion of the class function member.
Can you overload an protected method in Java?
Yes, protected methods of a superclass can be overridden by subclasses.
Can protected data members be inherited in derived class present in different package?
Protected allows access by subclasses and other classes in the same package. Thus, all Derived class instances have access to the protected methods of Base.
Who can access private data in a class?
Private: Class members declared as private can only be accessed by functions within the class. They cannot be accessed directly by objects or functions outside the class. Only member or friend functions can access private data members of a class.
Can we declare constructor as static?
No, you cannot define static constructors in Java. Attempting to define a constructor using the static keyword will result in a compile-time error. In general, static means at the class level. Constructors are used to assign initial values to instance variables.
Can a constructor be void?
Note that the constructor name must match the class name and cannot have a return type (e.g., void). Also note that the constructor is called when the object is created.