6. Errors

Activity 6.01: Creating a Custom Error Message for a Banking Application

Solution:

1. Create a directory called Activity6.01 inside your $GOPATH.
2. Save a file inside of the directory created in step 1 called main.go.
3. Define package main and import two packages, errors and fmt:

   package main
   import (
     «errors»
     «fmt»
   )

4. Next, define our custom error that will return an error that displays "invalid last name":

   var ErrInvalidLastName = errors.New("invalid last name")

5. We need one more custom error that will return an error that displays "invalid routing number":

   var ErrInvalidRoutingNum = errors.New("invalid routing number")

6. In the main() function, we will print each of the errors:

   func main() {
     fmt.Println(ErrInvalidLastName)
     fmt.Println(ErrInvalidRoutingNum)
   }

7. At the command line, navigate to the directory created in step 1.
8. At the command line...