Search results
Results From The WOW.Com Content Network
In software systems, encapsulation refers to the bundling of data with the mechanisms or methods that operate on the data. It may also refer to the limiting of direct access to some of that data, such as an object's components. [1] Essentially, encapsulation prevents external code from being concerned with the internal workings of an object.
Object composition refers to the logical or conceptual structure of the information, not the implementation or physical data structure used to represent it [citation needed]. For example, a sequence differs from a set because (among other things) the order of the composed items matters for the former but not the latter.
For example, a relational database is encapsulated in the sense that its only public interface is a query language (such as SQL), which hides all the internal machinery and data structures of the database management system. As such, encapsulation is a core principle of good software architecture, at every level of granularity.
In other words, the object-oriented interface to some service or system. Such an interface is said to be the object model of the represented service or system. For example, the Document Object Model (DOM) is a collection of objects that represent a page in a web browser , used by script programs to examine and dynamically change the page.
In computer programming, field encapsulation involves providing methods that can be used to read from or write to the field rather than accessing the field directly. Sometimes these accessor methods are called getX and setX (where X is the field's name), which are also known as mutator methods.
[1]: 78 An object can model some part of reality or can be an invention of the design process whose collaborations with other such objects serve as the mechanisms that provide some higher-level behavior. Put another way, an object represents an individual, identifiable item, unit, or entity, either real or abstract, with a well-defined role in ...
Data encapsulation, also known as data hiding, is the mechanism whereby the implementation details of a class are kept hidden from the user. The user can only perform a restricted set of operations on the hidden members of the class by executing special functions commonly called methods to prevent attributes of objects from being easily viewed and accessed.
For example, in the IP suite, the contents of a web page are encapsulated with an HTTP header, then by a TCP header, an IP header, and, finally, by a frame header and trailer. The frame is forwarded to the destination node as a stream of bits , where it is decapsulated into the respective PDUs and interpreted at each layer by the receiving node.