Powerful Command-Line Applications in Go

Handling Errors

At this point your application handles errors by defining error strings, using the function fmt.Errorf from package fmt. This is a valid approach for small applications, but it’s harder to maintain as your application grows in complexity. For instance, relying only on comparing the error message isn’t a resilient method as the error message may change.

As an alternative, in ​Developing the Initial Version of colStats​, you handled errors by defining error values as exported variables. You can use this approach here to handle simple errors, such as validating input parameters. Add a file errors.go to your project and edit it. Add the package definition and the import section. For this file, you’re using the package errors to ...