Uml

Unified Modeling Language has four common mechanisms that we can apply throughout

the language

(i) Specification

(ii) Common Divisions

(iii) Adornments

(iv) Extensibility mechanisms.

(i) Specifications:- The UML is more than a graphical language. Rather, behind every part of its graphical

notation there is a specification that provides a textual statement of the syntax and semantics of the building

block.

(ii) Adornments: – Notes are the most important kind of adornment that stands alone. A note is a graphical

symbol for rendering constraints attached to an element or a collection of elements.

(iii) Common Division:- In modeling Object Oriented systems, the world often gets divided in several ways.

First, there is the division of class and object.

A class is an abstraction; an object is one concrete manifestation of that abstraction.

Graphically, the UML distinguish an object by using the same symbol as its class and then simply underlying

the objects name.

(iv) Extensibility Mechanisms: – UML is opened ended language, making it possible for You to extend the

language in controlled ways:

There are three:-Stereotype:- Stereotype is used when you are modeling a network, you might want to have

symbols for routers and hubs; then we use stereotype nodes to make these things appear as primitive building

blocks.

Tagged value:- A tagged value extends the properties of UML building blocks ,Allowing user to create new

information in that elements specification.

Constraint: – This allows user to add new rules or modify existing ones.