l-vitaly

type TemperamentЕype int
const (
    TypicalSanguinePerson TemperamentЕype = iota // 0
    TypicalCholericSubject                       // 1
    TypicalPhlegmaticPerson                      // 2
    TypicalMelancholiac                          // 3
)

l-vitaly

func FormatMyValue(i int) string {
    return fmt.Sprintf(“there are %d my value”, i)
}

func main() {
    n := TypicalPhlegmaticPerson
    fmt.Println(FormatMyValue(n))
}

// output:

l-vitaly

type CarType int
const (
    BMW CarType = iota // 0
    Audi               // 1
    Mercedes           // 2
    _
    _
    XRay               // 5
)

l-vitaly

type Permissions int

const (
    Read Permissions = 1 << iota // 1 << 0 = 00000001
    Write                        // 1 << 1 = 00000010
    Create                       // 1 << 2 = 00000100
    Delete                       // 1 << 3 = 00001000
)

l-vitaly

fmt.Println(Write | Delete | Read)

// output:
// 11

l-vitaly

type ByteSize float64

const (
    _ = iota                       // ignore first value by assigning to blank identifier
    KB ByteSize = 1 << (10 * iota) // 1 << (10*1)
    MB                             // 1 << (10*2)
    GB                             // 1 << (10*3)
    TB                             // 1 << (10*4)
    PB                             // 1 << (10*5)
    EB                             // 1 << (10*6)

l-vitaly

const (
    Russia, USA = iota + 1, iota + 2
    Ukraine, Italy
    China, Spain
)

// Russia: 1
// USA: 2
// Ukraine: 2
// Italy: 3

l-vitaly

func UCFirst(s string) string {
  return strings.ToUpper(s[:1]) + s[1:]
}

func LCFirst(s string) string {
  return strings.ToLower(s[:1]) + s[1:]
}

l-vitaly

docker rm -v $(docker ps --filter status=exited -q 2>/dev/null) 2>/dev/null
docker rmi $(docker images --filter dangling=true -q 2>/dev/null) 2>/dev/null

l-vitaly

func sortMap(m map[string]string) []string {
	list := make(sort.StringSlice, len(m))
	i := 0
	for name := range m {
		list[i] = name
		i++
	}
	list.Sort()
	result := make([]string, len(list))
	for i, name := range list {