Summary

In this chapter, you've learned about the core classes. You've learned about issues with true, false, and nil, and how best to use Ruby's numeric types. You've learned why the difference between symbols and strings is important. You've learned how best to use arrays, hashes, and sets, and when it makes sense to use your own custom structs.

In the next chapter, you'll build on this knowledge of the core classes and learn about constructing your own custom classes.