Chapter 4. Arrays, slices, and maps
In this chapter
- Array internals and fundamentals
- Managing collections of data with slices
- Working with key/value pairs using maps
It’s difficult to write programs that don’t need to store and read collections of data. If you use databases or files, or access the web, you need a way to handle the data you receive and send. Go has three different data structures that allow you to manage collections of data: arrays, slices, and maps. These data structures are baked into the language and used throughout the standard library. Once you learn how these data structures work, programming in Go will become fun, fast, and flexible.
It makes sense to start with arrays because they form the base data structure for both slices and maps. Understanding how arrays work will help you appreciate the elegance and power that slices and maps provide.
An array in Go is a fixed-length data type that contains a contiguous block of elements of the same type. This could be a built-in type such as integers and strings, or it can be a struct type.
In figure 4.1 you can see the representation of an array. The elements of the array are marked as a grey box and are connected in series to each other. Each element contains the same type, in this case an integer, and can be accessed through a unique index position.
