What is meant by the term encapsulation as it is used in Object Oriented Analysis?

Answer 1

Encapsulation conceals the functional details of a class from objects that send messages to it.

For example, the Dog class has a bark() method. The code for the bark() method defines exactly how a bark happens (e.g., by inhale() and then exhale(), at a particular pitch and volume). Timmy, Lassie's friend, however, does not need to know exactly how she barks. Encapsulation is achieved by specifying which classes may use the members of an object. The result is that each object exposes to any class a certain interface - those members accessible to that class. The reason for encapsulation is to prevent clients of an interface from depending on those parts of the implementation that are likely to change in future, thereby allowing those changes to be made more easily, that is, without changes to clients. For example, an interface can ensure that puppies can only be added to an object of the class Dog by code in that class. Members are often specified as public, protected or private, determining whether they are available to all classes, sub-classes or only the defining class. Some languages go further: Java uses the default access modifier to restrict access also to classes in the same package, C# and VB.NET reserve some members to classes in the same assembly using keywords internal (C#) or Friend (VB.NET), and Eiffel and C++ allow one to specify which classes may access any member.

Answer 2

Encapsulation is the term used to describe the packaging of data and the functions that operate upon that data into a single component. The functions can be used to provide an interface to the data, such that the data can be manipulated in a controlled manner. In object oriented programming, this is achieved through classes instantiated as objects. Each object has its own discrete set of data and the class determines how that data may be manipulated. Classes typically encapsulate an invariant that must hold from the point of creation to the point of destruction. Limiting exposure of the object's data through a controlled public interface ensures that the invariant holds true throughout the object's life cycle without the need to constantly test the invariant.

For example, a string has an invariant in that it holds a null-terminated character array with a minimum size of 1 character (for the null terminator). The string class ensures that the array member remains valid throughout the life cycle of any instance of the class. Similarly, a vector has an invariant in that it holds a dynamic array with size and reserve, such that the total of the size and reserve members is equal to the length of the memory currently allocated to the array member.

Answer 3

when you pack the code and the data part in your program so that no one outside that class can change it ,It is a data hiding .For ex. Suppose you have a variable called "i " in your program if you provide public as a access modifier outside environment can change it.So we give it a modifier called "private" and provide getter() and setter() methods by this way outside environment can call these methods but no one can change it ..

Answer 4

Encapsulation is an object-oriented technique that helps restrict access to the protected members of a data structure. It does this by only exposing the structure through a generic public interface, whereby anything can use the interface without "harming" the structure.

Answer 5

Encapsulation is an important concept when it comes to Object Orientation programming. This is because encapsulation restricts the access to certain components. Also, it facilitates data.