USE CLASS DIAGRAM BLOG

How to Create Class Diagrams

To create and evolve a conceptual class diagram, you need to iteratively model:

Classes

Responsibilities

Associations

Inheritance relationships

Composition associations

Vocabularies

 

Class diagram : are the best design tool for development teams. This Diagram helps developers get the structure of the system before the code is written, and helps to ensure that the system is the best design.

Clas diagram used  : to display classes and packages in the system. Class a diagram give you a static system and relation between them. Usually, make some single class diagram to systems. Some will diagram showing a subset of classes and relatives. Can be made some diagram according to desirable to get a complete picture against system built.

 

 

 

Interfaces

The purpose of a class diagram is to depict the classes within a model. In an object oriented application,

classes have attributes (member variables), operations (member functions) and relation-ships with other classes. The UML class diagram can depict all these things quite easily. The

fundamental element of the class diagram is an icon the represents a class. This icon is shown in.

Classes are interrelated to each other in specific ways. In particular, relationships in class diagrams include different types of logical connections. The following are such types of logical connections that are possible in UML: 

• Association
• Directed Association
• Reflexive Association
• Multiplicity
• Aggregation
• Composition
• Inheritance/Generalization
• Realization

Association

is a broad term that encompasses just about any logical connection or relationship between classes

Directed Association

refers to a directional relationship represented by a line with an arrowhead.

Reflexive Association

occurs when a class may have multiple functions or responsibilities

Multiplicity

is the active logical association when the cardinality of a class in relation to another is being depicted

Aggregation

refers to the formation of a particular class as a result of one class being aggregated or built as a collection

Composition

is very similar to the aggregation relationship, with the only difference being its key purpose of emphasizing the dependence of the contained class to the life cycle of the container class.

Inheritance

refers to a type of relationship wherein one associated class is a child of another by virtue of assuming the same functionalities of the parent class

Realization

denotes the implementation of the functionality defined in one class by another class.

Simple class diagram with attributes and operations

In the example, a class called “loan account” is depicted. Classes in class diagrams are represented by boxes that are partitioned into three:

The top partition contains the name of the class.

The middle part contains the class’s attributes.

The bottom partition shows the possible operations that are associated with the class.

Those should be pretty easy to see in the example: the class being described is a loan account, some of whose attributes include the type of loan, the name of the borrower/loaner, the specific date the loan was released and the loan amount. As in the real world, various transactions or operations may be implemented on existing loans such as renew and extend.  The example shows how class diagrams can encapsulate all the relevant data in a particular scenario in a very systematic and clear way.

In object-oriented modeling, class diagrams are considered the key building blocks that enable information architects, designers, and developers to show a given system’s classes, their attributes, the functions or operations that are associated with them, and the relationships among the different classes that make up a system.