As discussed earlier, we can implement the concept of data encapsulation through classes and objects. In order to access data members and member functions in a class, we need to create objects in association with it, to create a block in the computer memory to store it.<\/p>\n
We can access these data members and member functions with objects by reading and printing them onto the screen. We can even perform data manipulation operations with the help of objects. Unless we create an object, C++ does not grant access to data members and member functions. Therefore, the data is not visible to the outside world and it is absolutely safe from inadvertent alteration.<\/p>\n
Example of Data Encapsulation<\/h3>\n
Let us consider a real-life problem in order to better understand the meaning of data encapsulation.<\/p>\n
Suppose you are a student and you want to access the answer key to the test you had given last week from your teacher. You do not have direct authority to go into the teacher\u2019s cabin and take away the answer key. You need to take permission from your teacher and then your teacher would go to her cabin herself and hand over the answer key to you.<\/p>\n
This practice ensures that data is in safe hands and cannot be corrupted by unsuitable users.<\/p>\n
It is safe is say that \u201cThe answer key (data) and the teacher (an object that helps you access the answer key) are encapsulated into a single unit. In a similar fashion, objects help you maintain the integrity of the program data.<\/p>\n
Let us try to implement the concept of data encapsulation in C++ with the help of a simple program.<\/p>\n
Consider a scenario where you want to secure the transaction ID from inadvertent users in the finance department. You can solve this problem by using the concept of data encapsulation.<\/p>\n
Example-<\/h4>\n
The C++ program given below shows how data is hidden from the outside world with reference to the above-stated scenario:<\/p>\n
#include<iostream> \r\nusing namespace std; \r\n\r\nclass Encapsulation \r\n{ \r\n\/\/ Private by default \/\/ Data inaccessible to the outside world\r\nlong int ID; \r\n\r\npublic:\r\n\r\nvoid set_value(int value) \r\n{ \r\nID = value;\r\n} \r\nint get_value() \r\n{ \r\nreturn ID; \r\n} \r\n}; \r\n\r\n\/\/ main function \r\nint main() \r\n{ \r\n\r\ncout<<\"Welcome to DataFlair tutorials!\"<<endl<<endl;\r\n\r\nEncapsulation e; \r\n\r\ne.set_value(209718); \r\ncout<<\"The ID is: \"<<e.get_value()<<endl;\r\nreturn 0; \r\n}<\/pre>\n <\/p>\n
![\"Output](\"https:\/\/data-flair.training\/blogs\/wp-content\/uploads\/sites\/2\/2019\/06\/Output-of-Example-of-Data-Encapsulation-in-C.jpg\")
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