Return values in time format

Question

I own a struct with 2 ints and I need to return these values in string but in time format.

type Clock struct {
    hour   int
    minute int
}

func New(hour, minute int) Clock {
    return Clock{hour, minute}
}

func (c Clock) String() string {
    return strconv.Itoa(c.hour) + ":" + strconv.Itoa(c.minute)
}

The return of function String() does not include the "zeros" due to the numbers as they are of the type inteiro.

retornado: "8:0", desejado "08:00"
retornado "10:3", desejado "10:03"

This challenge is to not use the date which already comes embedded just to the Go.

Answer 1

A very simple way would be to add 0 to the left until there are two numbers, you have the fmt.Sprintf you can do this. If you use it it would look like:

func (c Clock) String() string {
    return fmt.Sprintf("%02v:%02v", strconv.Itoa(c.hour), strconv.Itoa(c.minute))
}

But you in this case don’t need the strconv, could use:

func (c Clock) String() string {
    return fmt.Sprintf("%02d:%02d", c.hour, c.minute)
}

https://play.golang.org/p/nQi80Yj_vh

There are several options, including a for like this extremely simple:

func lpad(s, value string, length int) string {

    for len(s) < length {
        s = value + s
    }

    return s
}

https://play.golang.org/p/02gfYXqxRx

---

Golang has the Time which can be used for timing issues, adding dates, times and also allows you to convert to string...