So far we have covered what arrays and slices are, and how to work with them at a basic level. However, a big aspect of working with slices are that we can add elements and the slice will resize automatically. But how do we add to a slice?

Go provides us with a function, append that handles all of the logic of adding to and resizing a slice:

books := []string{"Tom Sawyer", "Of Mice and Men"}
books = append(books, "Frankenstein")
books = append(books, "Dracula")
fmt.Println(books)
// [Tom Sawyer Of Mice and Men Frankenstein Dracula]

Being able to add new elements to a slice is very important. Especially when data comes in over time that we cannot predict.

Let’s practice appending elements in a Go program!