The addCLA.go program revisited

This subsection will present an improved version of the addCLA.go program we developed in the previous chapter, to make it able to handle any kind of user input. The new program will be called addCLAImproved.go, but instead of presenting its full Go code, you will only see the differences between addCLAImproved.go and addCLA.go using the diff(1) command-line utility:

$ diff addCLAImproved.go addCLA.go
13,18c13,14
<           temp, err := strconv.Atoi(arguments[i])
<           if err == nil {
<                 sum = sum + temp
<           } else {
<                 fmt.Println("Ignoring", arguments[i])
<           }
---
>           temp, _ := strconv.Atoi(arguments[i])
>           sum = sum + temp

What this output basically tells us is that the last two lines of code, which can be found in addCLA.go and begin with the > character, were replaced by the lines of code that begin with the < character in addCLAImproved.go. The remaining code of both files is exactly the same.

Executing addCLAImproved.go will generate the following kind of output:

$ go run addCLAImproved.go
Sum: 0
$ go run addCLAImproved.go 1 2 -3
Sum: 0
$ go run addCLAImproved.go 1 a 2 b 3.2 @
Ignoring a
Ignoring b
Ignoring 3.2
Ignoring @
Sum: 3

So, the new and improved version works as expected, behaves reliably, and allows us to differentiate between valid and invalid input.