Although there is a tendency when first learning PHP to start writing scripts and typing huge sequences of code, we have shown you that PHP is a fully featured and robust language that allows us to plan our programs to share and reuse code. By defining functions, we can make repeated use of small chunks of code. By putting groups of functions and other script inside other files, we can increase the scale of our reuse and sharing to the point where multiple projects make use of the same code.
In the next chapter, we will take this notion of organizing and sharing code to a whole new level by introducing a system that can be used to create whole new data types, complete with attributes and their associated custom implementations. Also, object-oriented programming will let us create entirely new data types and structures that can be used to encapsulate functional areas of our applications.