C++

DATA TYPE	SIZE (IN BYTES)	RANGE
short int	2	-32,768 to 32,767
unsigned short int	2	0 to 65,535
unsigned int	4	0 to 4,294,967,295
int	4	-2,147,483,648 to 2,147,483,647
long int	4	-2,147,483,648 to 2,147,483,647
unsigned long int	4	0 to 4,294,967,295
long long int	8	-(2^63) to (2^63)-1
unsigned long long int	8	0 to 18,446,744,073,709,551,615
signed char	1	-128 to 127
unsigned char	1	0 to 255
float	4
double	8
long double	12
wchar_t	2 or 4	1 wide character

  

What is Encapsulation?

Encapsulation is an Object Oriented Programming concept that binds together the data and functions that manipulate the data, and that keeps both safe from outside interference and misuse. Data encapsulation led to the important OOP concept of data hiding.

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.

Data Encapsulation Example

Any C++ program where you implement a class with public and private members is an example of data encapsulation and data abstraction. Consider the following example −

#include <iostream>

using namespace std;

class Adder {

   public:

      // constructor

      Adder(int i = 0) {

         total = i;

      }

      // interface to outside world

      void addNum(int number) {

         total += number;

      }

      // interface to outside world

      int getTotal() {

         return total;

      };

      private:

      // hidden data from outside world

      int total;

};

int main() {

   Adder a;

   a.addNum(10);

   a.addNum(20);

   a.addNum(30);

   cout << "Total " << a.getTotal() <<endl;

   return 0;

}

When the above code is compiled and executed, it produces the following result – 60

Above class adds numbers together, and returns the sum. The public members addNum and getTotal are the interfaces to the outside world and a user needs to know them to use the class. The private member total is something that is hidden from the outside world, but is needed for the class to operate properly.