封装和抽象之间的确切区别是什么?
当前回答
抽象:抽象的意思是显示功能的哪一部分。
封装:封装意味着隐藏功能的How部分。
让我们举一个非常简单的例子
/// <summary>
/// We have an Employee class having two properties EmployeeName and EmployeeCode
/// </summary>
public class Employee
{
public string EmplpyeeName { get; set; }
public string EmployeeCode { get; set; }
// Add new employee to DB is the main functionality, so are making it public so that we can expose it to external environment
// This is ABSTRACTION
public void AddEmployee(Employee obj)
{
// "Creation of DB connection" and "To check if employee exists" are internal details which we have hide from external environment
// You can see that these methods are private, external environment just need "What" part only
CreateDBConnection();
CheckIfEmployeeExists();
}
// ENCAPLUSATION using private keyword
private bool CheckIfEmployeeExists()
{
// Here we can validate if the employee already exists
return true;
}
// ENCAPLUSATION using private keyword
private void CreateDBConnection()
{
// Create DB connection code
}
}
控制台应用程序程序类
class Program
{
static void Main(string[] args)
{
Employee obj = new Employee();
obj.EmplpyeeName = "001";
obj.EmployeeCode = "Raj";
// We have exposed only what part of the functionality
obj.AddEmployee(obj);
}
}
其他回答
让我用简单的代码示例来尝试一下
抽象=数据隐藏+封装
// Abstraction
interface IOperation
{
int GetSumOfNumbers();
}
internal class OperationEven : IOperation
{
// data hiding
private IEnumerable<int> numbers;
public OperationEven(IEnumerable<int> numbers)
{
this.numbers = numbers;
}
// Encapsulation
public int GetSumOfNumbers()
{
return this.numbers.Where(i => i % 2 == 0).Sum();
}
}
class Aeroplane : IFlyable, IFuelable, IMachine
{ // Aeroplane's Design says:
// Aeroplane is a flying object
// Aeroplane can be fueled
// Aeroplane is a Machine
}
// But the code related to Pilot, or Driver of Aeroplane is not bothered
// about Machine or Fuel. Hence,
// pilot code:
IFlyable flyingObj = new Aeroplane();
flyingObj.Fly();
// fighter Pilot related code
IFlyable flyingObj2 = new FighterAeroplane();
flyingObj2.Fly();
// UFO related code
IFlyable ufoObj = new UFO();
ufoObj.Fly();
// **All the 3 Above codes are genaralized using IFlyable,
// Interface Abstraction**
// Fly related code knows how to fly, irrespective of the type of
// flying object they are.
// Similarly, Fuel related code:
// Fueling an Aeroplane
IFuelable fuelableObj = new Aeroplane();
fuelableObj.FillFuel();
// Fueling a Car
IFuelable fuelableObj2 = new Car(); // class Car : IFuelable { }
fuelableObj2.FillFuel();
// ** Fueling code does not need know what kind of vehicle it is, so far
// as it can Fill Fuel**
抽象让您关注对象做了什么,而不是它是如何做的 封装意味着隐藏对象如何做某事的内部细节或机制。
就像你开车时,你知道油门踏板的作用,但你可能不知道它背后的过程,因为它是封装的。
让我用c#举个例子。假设你有一个整数:
int Number = 5;
string aStrNumber = Number.ToString();
你可以使用像number . tostring()这样的方法,它返回数字5的字符表示,并将其存储在字符串对象中。该方法告诉您它做了什么,而不是如何做。
我认为封装是实现抽象的一种方式。看看下面的链接。
抽象和封装
通过使用单个通用示例进行抽象和封装
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