Level Up Your Web Apps With Go

Chapter 2Go Types Explored

In the last chapter, we were introduced to the basic Go types and syntax. In this chapter we’ll go a little deeper into some of the types, and how to define your own types and interfaces. We’ll also cover how Go lets us use third-party libraries in our software with ease.

Custom Types

While you can’t add your own methods to built-in types, you can create your own types from other types. A common example of this is a ByteSize type, which extends float64 and provides a custom formatted string to represent a size in bytes such as 2 kilobytes or 3.14 megabytes:

const ( KB = 1024 MB = KB * 1024 GB = MB * 1024 TB = GB * 1024 PB = TB * 1024 ) type ByteSize float64 func (b ByteSize) String() string { switch { case b >= PB: ...