So far, we have taken a deep dive into key-value coding and other details such as various implementation methods, their advantages and disadvantages, and also key-value observing—a mechanism built on top of key-value coding.

We also saw some working code for key-value coding and key-value observing with some explanation on why we prefer to use key-value coding over other similar methods such as using a dot operator to access properties.

With this, I hope all these will help to give you an understanding of key-value coding and key-value observing. So with this, let's move on to the next chapter where we will wade into the brand new language by Apple called Swift.