Editing Command pattern (section)

== Structure ==
=== UML class and sequence diagram ===
[[File:w3sDesign Command Design Pattern UML.jpg|frame|none|A sample UML class and sequence diagram for the Command design pattern. <ref>{{cite web |title=The Command design pattern - Structure and Collaboration |url=http://w3sdesign.com/?gr=b02&ugr=struct |archive-url=https://web.archive.org/web/20200923120537/http://w3sdesign.com/?gr=b02&ugr=struct |url-status=dead |archive-date=September 23, 2020 |access-date=2017-08-12 |website=w3sDesign.com}}</ref>]]

In the above [[Unified Modeling Language|UML]] [[class diagram]], the <code>Invoker</code> class doesn't implement a request directly.
Instead, <code>Invoker</code> refers to the <code>Command</code> interface to perform a request (<code>command.execute()</code>), which makes the <code>Invoker</code> independent of how the request is performed.
The <code>Command1</code> class implements the <code>Command</code> interface by performing an action on a receiver (<code>receiver1.action1()</code>).
 
The [[Unified Modeling Language|UML]] [[sequence diagram]]
shows the run-time interactions: The <code>Invoker</code> object calls <code>execute()</code> on a <code>Command1</code> object.
<code>Command1</code> calls <code>action1()</code> on a <code>Receiver1</code> object,
which performs the request.

=== UML class diagram ===
[[File:Command pattern.svg|thumb|700px|center|UML diagram of the command pattern]]