What is the use of this pointer?

Every object in C++ has access to its own address through an important pointer called this pointer. The this pointer is an implicit parameter to all member functions. Therefore, inside a member function, this may be used to refer to the invoking object.

Hereof, what is virtual function with example?

A virtual function a member function which is declared within base class and is re-defined (Overriden) by derived class.When you refer to a derived class object using a pointer or a reference to the base class, you can call a virtual function for that object and execute the derived class’s version of the function.

Why do we need virtual function?

Virtual Functions are used to support ” Run time Polymorphism”. When the virtual function is called by using a Base Class Pointer, the Compiler decides at Runtime which version of the function i.e. Base Class version or the overridden Derived Class version is to be called. This is called Run time Polymorphism.

What is the purpose of the virtual keyword C++?

Virtual keyword determines if a member function of a class can be over-ridden in its derived classes. The non-virtual member functions are resolved at compiling time and it’s called static binding. However, the c++ virtual member functions are resolved during runtime and it’s called as dynamic binding.

Can I use this in constructor?

Some people feel you should not use the this pointer in a constructor because the object is not fully formed yet. However you can use this in the constructor (in the {body} and even in the initialization list) if you are careful.

What is a member function?

Member functions are operators and functions that are declared as members of a class. Member functions do not include operators and functions declared with the friend specifier. These are called friends of a class. You can declare a member function as static ; this is called a static member function.

What is the use of friend function in C++?

C++ Friend Functions. Advertisements. A friend function of a class is defined outside that class’ scope but it has the right to access all private and protected members of the class. Even though the prototypes for friend functions appear in the class definition, friends are not member functions.

Can we use this pointer inside static member function?

It is the object address value as a pointer. For static functions there is no object address at all because static function can be called even before creation of any object using scope resolution operator. Thus this pointer is not available in any static function.

What is a friend function?

In object-oriented programming, a friend function, that is a “friend” of a given class, is a function that is given the same access as methods to private and protected data. A friend function is declared by the class that is granting access, so friend functions are part of the class interface, like methods.

What is a copy constructor?

The copy constructor is a constructor which creates an object by initializing it with an object of the same class, which has been created previously. The copy constructor is used to − Initialize one object from another of the same type. Copy an object to pass it as an argument to a function.

What does this pointer points to?

The this pointer is a pointer accessible only within the nonstatic member functions of a class, struct , or union type. It points to the object for which the member function is called. Static member functions do not have a this pointer.

What do you mean by pure virtual functions?

A pure virtual function or pure virtual method is a virtual function that is required to be implemented by a derived class if the derived class is not abstract. Classes containing pure virtual methods are termed “abstract” and they cannot be instantiated directly.

What is a virtual function?

A virtual function is a member function that you expect to be redefined in derived classes. When you refer to a derived class object using a pointer or a reference to the base class, you can call a virtual function for that object and execute the derived class’s version of the function.

What is the use of scope resolution operator?

Scope resolution operator :: (C++ only) The :: (scope resolution) operator is used to qualify hidden names so that you can still use them. You can use the unary scope operator if a namespace scope or global scope name is hidden by an explicit declaration of the same name in a block or class.

What is a static function in C++?

Static Members of a C++ Class. Advertisements. We can define class members static using static keyword. When we declare a member of a class as static it means no matter how many objects of the class are created, there is only one copy of the static member. A static member is shared by all objects of the class.

What is the use of this keyword in Java?

Keyword ‘THIS’ in Java is a reference variable that refers to the current object. It can be used to refer current class instance variable. It can be used to invoke or initiate current class constructor. It can be passed as an argument in the method call.

What is the use of inline function in C++?

The inline functions are a C++ enhancement feature to increase the execution time of a program. Functions can be instructed to compiler to make them inline so that compiler can replace those function definition wherever those are being called.

What is the use of constant member function in C++?

Const member functions in C++ A function becomes const when const keyword is used in function’s declaration. The idea of const functions is not allow them to modify the object on which they are called. When a function is declared as const, it can be called on any type of object.

What is a non static member function in C++?

A non-static member function can be declared with a const, volatile, or const volatile qualifier (this qualifier appears after the parameter list in the function declaration). (A non-const member function may still be called if const_cast is applied or through an access path that does not involve this.)

What is the use of new operator in C++?

When new is used to allocate memory for a C++ class object, the object’s constructor is called after the memory is allocated. Use the delete operator to deallocate the memory allocated with the new operator.

What is a pointer in C++?

The variable that stores the address of another variable (like foo in the previous example) is what in C++ is called a pointer. Pointers are a very powerful feature of the language that has many uses in lower level programming.

What is the use of const in C++?

Const means that a pointer or reference cannot be used for a write or read-modify-write operation without casting away const. It does NOT mean what the C++ standard tries to claim it means (the C++ standard is just wrong on this).

What do you mean by constructor in C++?

A constructor is a kind of member function that initializes an instance of its class. A constructor has the same name as the class and no return value. A constructor can have any number of parameters and a class may have any number of overloaded constructors.

What is a container in C++?

The Standard Template Library (STL) is a set of C++ template classes to provide common programming data structures and functions such as lists, stacks, arrays, etc. It is a library of container classes, algorithms and iterators. It is a generalized library and so, its components are parameterized.