What is encapsulation in C++?

 In normal terms, 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 manipulate them.

Consider a real-life example of encapsulation, in a company, there are different sections like the accounts section, finance section, sales section, etc. The finance section handles all the financial transactions and keeps records of all the data related to finance. Similarly, the sales section handles all the sales-related activities and keeps records of all the sales. Now there may arise a situation when for some reason an official from the finance section needs all the data about sales in a particular month. In this case, he is not allowed to directly access the data of the sales section. He will first have to contact some other officer in the sales section and then request him to give the particular data. This is what encapsulation is. Here the data of the sales section and the employees that can manipulate them are wrapped under a single name “sales section”.

Encapsulation also leads to data abstraction or hiding. Using encapsulation also hides the data. In the above example, the data of any of the sections like sales, finance, or accounts are hidden from any other section.

In C++ encapsulation can be implemented using Class and access modifiers. Look at the below program:

// c++ program to explain
// Encapsulation

#include
using namespace std;

class Encapsulation
{
	private:
		// data hidden from outside world
		int x;
		
	public:
		// function to set value of
		// variable x
		void set(int a)
		{
			x =a;
		}
		
		// function to return value of
		// variable x
		int get()
		{
			return x;
		}
};

// main function
int main()
{
	Encapsulation obj;
	
	obj.set(5);
	
	cout<<obj.get();
	return 0;
}

In the above program, the variable x is made private. This variable can be accessed and manipulated only using the functions get() and set() which are present inside the class. Thus we can say that here, the variable x and the functions get() and set() are bound together which is nothing but encapsulation.