You've got Visitor down.
What you covered
💡 The Bottom Line, one more time
Visitor pattern explained: represent an operation to be performed on elements of an object structure without changing their classes.
What's next
Visitor is one of 23 classic Gang-of-Four patterns. From here, the natural next step is:
- Explore more patterns — see the full Design Patterns track for all 23, grouped by Creational, Structural, and Behavioral.
- SOLID Design Principles — many patterns, including this one, are concrete applications of SOLID principles.