Binding the data members and member functions together into a single class is called
Pushkar Kumar Published Feb 2, 2019 The four pillars for OOP are Abstraction, Encapsulation, Inheritance, Polymorphism. Correct me if anything is wrong. Sources: books. Others also viewedExplore topicsGet this book -> Problems on Array: For Interviews and Competitive Programming Reading time: 45 minutes | Coding time: 5 minutes The main purpose of C++ programming is to add object orientation to the C programming language and classes are the central feature of C++ that supports object-oriented
programming and are often called A class is a mechanism for creating user-defined data types. It is similar to the C language structure data type. In C, a structure is composed of a set of data members. In C++, a class type is like a C structure, except that a class is composed of a set of data members and a set of operations that can be performed on the class. In other words, these are the building block of C++ that leads to Object Oriented
programming.It is a user defined data type, which holds its own data members and member functions, which can be accessed and used by creating an instance of that class. A class is like a All in all, it can also be said that a class is a way to bind the data and its associated functions together in a single unit. This process is called Encapsulation. Example-1:Class of birds, all birds can fly and they all have wings and beaks. So here flying is a behavior and wings and beaks are part of their characteristics. And there are many different birds in this class with different names but they all posses this behavior and characteristics. That means, a Class is just a blue print, which declares and defines characteristics and behavior, namely data members and member functions respectively. And all objects of this class will share these characteristics and behavior. Example-2:Consider the Class of Cars. There may be many cars with
different names and brand but all of them will share some common properties like all of them will have 4 wheels, Speed Limit, Mileage range etc. So here, Car is the class and wheels, speed limits, mileage are their properties. C++ ClassWhen we define a class, we define a blueprint for a data type. This doesn't actually define any data, but it does
define what the class name means, that is, what an object of the class will consist of and what operations can be performed on such an object.
In the above example, the keyword public determines the access attributes of the members of the class that follows it. A public member can be accessed from outside the class anywhere within the scope of the class object. We can also specify the members of a class as private or protected. An Object is an Objects are instances of class, which holds the data variables declared in class and the member functions work on these class objects. Each object has different data variables. Objects are initialised using special class functions called And whenever the object is out of its scope, another special class member function called In C++, object is a group of similar objects. It is a template from which objects are created. It can have fields, methods, constructors etc.
Both of the objects Box1 and Box2 will have their own copy of data members.
Accessing data members and member functions :The data members and member functions of class can be accessed using the 1. Accessing data members :-Example-1 : if the name of object is obj and you want to access the member function with the name printName() then you will have to write obj.printName(). Example-2:
Output :The output of above example-2 is as follows :
Example-3: Initialize and Display data through method
Output :
2. Member Functions :A member function of a class is a function that has its definition or its prototype within the class definition like any other variable. It operates on any object of the class of which it is a member, and has access to all the members of a class for that object. There are 2 ways to define a member function:
Defining a member function within the class definition declares the function inline, even if we do not use the inline specifier. If the member function is defined inside the class definition it can be defined directly, but if its defined outside the class, then we have to use the scope resolution 1. Inside class definition :If we define the function inside class then we don't not need to declare it first, we can directly define the function. Example -
Output :-
2. Outside class definition :But if we plan to define the member function outside the class definition then we must declare the function inside class definition and then define it outside. Example -
Output :-
Calling Class Member Function in C++
Output :-
Types of Member Functions :-
1. Simple Member functions :-These are the basic member function, which dont have any special keyword like static etc as prefix. All the general member functions, which are of below given form, are termed as simple and basic member functions. Syntax :
2. Static Member functions :-Static is something that holds its position. Static is a keyword which can be used with data members as well as the member functions. We will discuss this in details later. As of now we will discuss its usage with member functions only. These functions cannot access ordinary data members and member functions, but only It can be called using the object and the direct member access example :-
3. Const Member functions :-Const keyword makes variables constant, that means once defined, there values can't be changed.When used with member function, such member functions can never modify the object or its related data members. Syntax :-
Example -
4. Inline functions :-All the member functions defined inside the class definition are by default declared as Inline. Inline functions are actual functions, which are For an inline function, declaration and definition must be done together. For example -
Example -
Output :
Important Points About Inline Functions :-
5. Friend functions :-Friend functions are actually
not a class member function. Friend functions are made to give private access to non-class functions. We can declare a global function as friend, or a member function of other class as friend. Syntax:-
Characteristics of a Friend function:
Example-1:
Output :-
Example when the function is friendly to two classes :-
Output :-
What does binding of data and functions together in one unit called as?Encapsulation is defined as wrapping up of data and information under a single unit. In Object Oriented Programming, Encapsulation is defined as binding together the data and the functions that manipulates them.
What is the technique of binding both data and functions together?Data encapsulation is a mechanism of bundling the data, and the functions that use them and data abstraction is a mechanism of exposing only the interfaces and hiding the implementation details from the user.
What is the process of combining data members and functions in a single unit called class?Encapsulation is a process of combining member functions and data members in a single unit called a class. The purpose is to prevent access to the data directly. Access to them is provided through the functions of the class.
Is binding or wrapping data and methods in one single unit?Encapsulation is defined as the wrapping up of data under a single unit. It is the mechanism that binds together code and the data it manipulates.
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