Blog
16 BEST Note Taking App for Mac (2021)
Note-taking apps are the online notebooks, and because they're digital, you can do much more than...
Relationships in UML are used to represent a connection between structural, behavioral, or grouping things. It is also called a link that describes how two or more things can relate to each other during the execution of a system. Type of UML Relationship are Association, Dependency , Generalization , and Realization.
Lets study them in detail
It is a set of links that connects elements of the UML model. It also defines how many objects are taking part in that relation.
In a dependency relationship, as the name suggests, two or more elements are dependent on each other. In this kind of a relationship, if we make a change to a particular element, then it is likely possible that all the other elements will also get affected by the change.
It is also called a parent-child relationship. In generalization, one element is a specialization of another general component. It may be substituted for it. It is mostly used to represent inheritance.
In a realization relationship of UML, one entity denotes some responsibility which is not implemented by itself and the other entity that implements them. This relationship is mostly found in the case of interfaces.
In this UML tutorial, you will learn:
It is a structural relationship that represents objects can be connected or associated with another object inside the system. Following constraints can be applied to the association relationship.
We can also create a class that has association properties; it is called as an association class.
The reflexive association is a subtype of association relationship in UML. In a reflexive association, the instances of the same class can be related to each other. An instance of a class is also said to be an object.
Reflexive association states that a link or a connection can be present within the objects of the same class.
Let us consider an example of a class fruit. The fruit class has two instances, such as mango and apple. Reflexive association states that a link between mango and apple can be present as they are instances of the same class, such as fruit.
As the name suggests, the directed association is related to the direction of flow within association classes.
In a directed association, the flow is directed. The association from one class to another class flows in a single direction only.
It is denoted using a solid line with an arrowhead.
Example:
You can say that there is a directed association relationship between a server and a client. A server can process the requests of a client. This flow is unidirectional, that flows from server to client only. Hence a directed association relationship can be present within servers and clients of a system.
Using a dependency relationship in UML, one can relate how various things inside a particular system are dependent on each other. Dependency is used to describe the relationship between various elements in UML that are dependent upon each other.
It is a relationship between a general entity and a unique entity which is present inside the system.
In a generalization relationship, the object-oriented concept called inheritance can be implemented. A generalization relationship exists between two objects, also called as entities or things. In a generalization relationship, one entity is a parent, and another is said to be as a child. These entities can be represented using inheritance.
In inheritance, a child of any parent can access, update, or inherit the functionality as specified inside the parent object. A child object can add its functionality to itself as well as inherit the structure and behavior of a parent object.
This type of relationship collectively known as a generalization relationship.
Generalization relationship contains constraints such as complete, incomplete to check whether all the child entities are being included in the relationship or not.
In a realization relationship of UML, one entity denotes some responsibility which is not implemented by itself and the other entity that implements them. This relationship is mostly found in the case of interfaces.
Realization can be represented in two ways:
In the above diagram, account business rules realize the interface IRuleAgent.
In a realization relationship of UML, the canonical form is used to realize interfaces across the system. It uses an interface stereotype to create an interface and realization relationship is used to realize the particular interface.
In a canonical form, the realization relationship is denoted using the dashed directed line with a sizeable open arrowhead.
In the above diagram, interface Iruleagent is realized using an object called as Account Business Rules.
Realization in the UML class diagram can also be shown using an elided form. In an elided form, the interface is denoted using a circle which is also called as a lollipop notation.
This interface, when realized using anything present inside the system, creates an elided structure.
In the above diagram, the interface Iruleagent is denoted using an elided form which is being realized by acctrule.dll.
It is not a standard UML relationship, but it is still used in various applications.
Composite aggregation is a subtype of aggregation relation with characteristics as:
Composite aggregation is described as a binary association decorated with a filled black diamond at the aggregate (whole) end.
A folder is a structure which holds n number of files in it. A folder is used to store the files inside it. Each folder can be associated with any number of files. In a computer system, every single file is a part of at least one folder inside the file organization system. The same file can also be a part of another folder, but it is not mandatory. Whenever a file is removed from the folder, the folder stays un-affected whereas the data related to that particular file is destroyed. If a delete operation is executed on the folder, then it also affects all the files which are present inside the folder. All the files associated with the folder are automatically destroyed once the folder is removed from the system.
This type of relationship in UML is known by composite aggregation relationship.
An aggregation is a subtype of an association relationship in UML. Aggregation and composition are both the types of association relationship in UML. An aggregation relationship can be described in simple words as " an object of one class can own or access the objects of another class."
In an aggregation relationship, the dependent object remains in the scope of a relationship even when the source object is destroyed.
Let us consider an example of a car and a wheel. A car needs a wheel to function correctly, but a wheel doesn't always need a car. It can also be used with the bike, bicycle, or any other vehicles but not a particular car. Here, the wheel object is meaningful even without the car object. Such type of relationship is called an aggregation relation.
Note-taking apps are the online notebooks, and because they're digital, you can do much more than...
IT Service Management, which is popularly known (ITSM) aims to align the delivery of information...
Sublime Text is source code editor majorly used for the MAC platform. It offers native support for...
Virtual Card providers help you to get the computer-generated credit/debit card (not physical...
1) What is ServiceNow? ServiceNow is a cloud-based IT Service Management tool. It offers a single...
What is Continuous Integration? Continuous integration is a software development method where...