This chapter will talk about many essential, interesting, and handy Go topics that will help you be more productive. I think it would be a good idea to start this chapter by compiling and running the Go code of the hw.go program from the previous chapter. Then, you will learn how to deal with the environment variables that can be used by Go, how to process the command-line arguments of a Go program, and how to print the output on the screen and get input from the user. Finally, you will see how to define functions in Go, learn about the extremely important defer keyword, look at the data structures that come with Go, and learn what Go interfaces are before checking out code that generates random numbers.
Therefore, ...
