The composite design pattern
The composite design pattern is used to describe groups of objects that should be treated the same way as a single one.
Note
Its purpose is to compose objects into tree structures to represent whole-part hierarchies.
The composite design pattern is useful for removing code duplication and avoiding errors in cases where groups of objects are generally treated the same way. A popular example could be a file system in which we have directories, which can have other directories or files. Generally, the interface to interact with directories and files is the same, so they are good candidates for a composite design pattern.
Class diagram
As we mentioned previously, file systems are a good candidate for the composite design pattern. Essentially, they are just tree structures, so for our example, we will show how to build a tree using the composite design pattern.
The following figure shows our class diagram:
As you can see from the preceding diagram, Tree is our composite...
