Visitor

The Visitor design pattern represents an operation to be performed on the elements of an object structure. This pattern lets you define a new operation without changing the classes of the elements on which it operates.

Usage          Low

UML class diagram

A visualization of the classes and objects participating in this pattern.

Sample code

This structural code demonstrates the Visitor pattern in which an object traverses an object structure and performs the same operation on each node in this structure. Different visitor objects define different operations.

Output

See also

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• Common Design Patterns
• Design Guidelines
• Documentation