This isn’t a particularly high quality article. First example should just be
fmt.Println("Go", "is great!")
Also the author either misunderstands what bash is or is dumbing the jargon down so much that they’re misleading the readers what bash is. However most of the “bash commands” are not bash builtins but rather Linux coreutils. Those same commands would work the same in any shell on any OS with the GNU coreutils installed. But they wouldn’t work on any system running Bash and an alternate coreutils.
If one wants to learn go there are much better resources online.
All that aside, some of the Go code here is not optimal or “standard”. Take the first example, it uses appending instead of using the more performant strings.Builder.
If one wants to learn go there are much better resources online.