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What is a form diagram used for?

Form diagrams are used in software technology to describe the structure of a organization. A class diagram uses Unified Modeling Linguistic communication (UML) to show the classes, attributes, methods (or operations), and their relationships to each other, in the system. Essential to object-oriented modeling, a form diagram tin can be used to model the data structure or to design the organisation in particular.

In a class diagram, a class is any group of objects in the organization that share like roles. These classes have relationships to each other. The course can be considered a blueprint for objects, as they are used to define objects in the system and decide what they can exercise and how they are created.

For a developer, a class diagram provides the opportunity to sketch out the static view of an awarding or system before any coding begins. This can be vital for communicating requirements to stakeholders and for optimizing development or even maintenance at later stages in the project.

The basic elements used to create a grade diagram are the class proper name, attributes, and methods (or operations). Classes are usually represented by a rectangle with iii distinct sections separated by horizontal lines.

Class name

Each class is represented past a rectangle in the diagram, with the proper name of the class in the top office. Grade names are unremarkably centered, written in bold, and first with a capital letter.

Attributes

Attributes are data elements that are independent in every object of a grade and accept a value for each of these objects. Attributes are shown in the middle of the class rectangle, are aligned left, and the first letter is lowercase (note that it is very common to use camelCase for both attributes and methods).

Methods (operations)

Classes accept particular operations for dealing with communication with other classes. Methods are shown in the bottom role of the class rectangle and, like attributes, are aligned left with the first letter of the alphabet in lowercase.

The visibility of both attributes and methods can be specified by means of symbols before the name. + means public, - means individual, # means protected, ~means package.
If an attribute or method is derived from other values in the system, this can be indicated with a / before the name.
Both attributes and methods can also have extra parameters, such as type, initial values, and constraints.

Gleek enables you to create a class with its attributes and methods with just a few lines of the unique Gleek syntax.

Relationships

The connections between classes are chosen relationships. There are several different types, each shown with its own connecting line, either with or without an arrow at the end.

Clan

Clan indicates a static relationship between two classes. Clan relationships will usually include text to explain the nature of the human relationship.

Aggregation

Aggregation shows that i or more classes are part of another course, or are independent by it. However, if all the contained classes are removed, the container will persist.

Composition

Limerick is a stronger relationship than aggregation. It indicates that the classes contained depend upon the existence of the container. If the container class is removed, they cannot persist.

Dependency

Dependency indicates that one class depends on another, in that a change in one class may outcome in changes in the other.

Multiplicity

Multiplicity is an clan relationship and indicates that at least one of the 2 classes refers to the other when creating instances of itself. In other words, information technology shows the cardinality of the relationship.

Generalization/inheritance

When a detail class is considered to be a child of another class, it will inherit the same functionalities of the parent class. The specific class provides additional backdrop to the parent class, just is still compatible with information technology.

Realization/implementation

This indicates that a detail class is responsible for the implementation of some of the functionality of another class. The relationship defines this functionality for the class that is implementing, or realizing, it.

Informal class diagrams

While class diagrams make use of UML, which is a standardized modeling linguistic communication with certain conventions, they are non usually intended by developers to exist formal, rigidly divers diagrams that perfectly correspond to the system being visualized or designed. They are more oft used equally breezy tools to convey ideas and sketch out a system. That ways that yous are free to create whatever form diagram works for your needs.

Luckily, Gleek is a super-fast mode to go your ideas out of your head and onto the screen. Read our brusque syntax summary, and so caput over to Gleek to outset making a class diagram – no mouse required!

How to create a UML form diagram in Gleek

1. Create your starting time class. We can just name this "Grade". It will exist drawn equally a standard rectangle, with space for the attributes and methods.

2. Add an aspect with the TAB central to indent the lawmaking.

3. Add method with TAB and add "()" at the end so that Gleek knows it'due south a method!

4. Now for relationships between classes. Y'all can connect 2 classes with a solid line using "--"

v. Connect two classes with a dashed line using "-.-"

half-dozen. Connect two classes with an association pointer using "-->"

vii. Connect two classes with an inheritance arrow using "--*>"

viii. Connect two classes with an aggregation arrow using "--<>"

ix. Connect two classes with a composition arrow using "--<*>"

10. Connect ii classes with a dependency arrow using "-.->"

xi. Connect two classes with a realization/implementation pointer using "-.-*>"

12. You lot tin depict the connection between 2 classes with "-.Text->"

13. Assign multiplicity/cardinality using {1}--{1..*}, {0..*--{1} so on.

14. Finally, you tin add notation to any grade with ":" and and then choose i of the post-obit standard options in Gleek: interface, abstract, service, and enumeration. How you utilize these will depend on your particular needs. Y'all can also decide to stick with the standard rectangle.

Create diagram

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Source: https://www.gleek.io/uml-class-diagrams.html