Learning Golang, Day 11 – I Solved the Stringers Exercise!

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Well, while I did implement the solution today, it was yesterday when I felt that I was on the right track, encouraged by Peter Hellberg in the #newbies channel of https://gophers.slack.com[gophers.slack.com]. Thanks, Peter!

If you’ve not read https://go.dev/tour/methods/18[the problem definition], it’s:

Make the IPAddr type implement fmt.Stringer to print the address as a dotted quad. For instance, IPAddr{1, 2, 3, 4} should print as “1.2.3.4”.

Here’s my solution, which uses a combination of the append() function, fmt.Sprintf(), and strings.Join().

[source,go]

package main

import ( “fmt” “strings” )

type IPAddr [4]byte

func (ipa IPAddr) String() string { var output []string for _, v := range ipa { output = append(output, fmt.Sprintf("%d", v)) }

return strings.Join(output, ".")

}

func main() { hosts := map[string]IPAddr{ “loopback”: {127, 0, 0, 1}, “googleDNS”: {8, 8, 8, 8}, } for name, ip := range hosts { fmt.Printf("%v: %v\n", name, ip) } }

I had a good think about several, possible ways that I could approach this, but kept thinking that Go had to have something analogous to https://www.php.net/manual/en/function.implode.php[PHP's implode() method]. If you’re not familiar with implode, it joins the elements of an array together with a given string. So, the following example, would print out: James, Jodie, Matthew, Michael.

[source,php]

A byte in Go is an unsigned 8-bit integer. It has type uint8. A byte has a limit of 0 – 255 in numerical range. > It can represent an ASCII character. Given that knowledge I used `%d` with https://gobyexample.com/string-formatting[fmt.Sprintf()] to format each byte as a base-10 integer and return its string equivalent. I don't know if it's the best solution, but it's succinct and clear (to me). How would you have implemented `String()`? Share your thoughts in the comments, and **see you, link:/learning-golang/day-12[next time]!**