Question

我使用enum来定义id和文本值之间的关系，但是我使用id作为枚举值，因为我不能使用id作为变量名

type Gender uint8
type MemberType uint8

const (
    Male Gender = 2
    Female Gender = 5

    Standard MemberType = 2
    VIP MemberType = 5
)

现在我已经从“性别”表和“会员类型”表中选择了ID 5，如何使用它来获取“性别”的文本“女性”和“会员类型”的文本“ VIP”？

Answer 1

将所选ID设置为Gender类型。示例：

selectedID := 5
selectedGender := Gender(selectedID)
fmt.Println(selectedGender == Female) // true

anotherSelectedID := 5
selectedMemberType := MemberType(anotherSelectedID)
fmt.Println(selectedMemberType == VIP) // true

游乐场：https://play.golang.org/p/pfmJ0kg7cO3

Answer 2

如果您尝试获取字符串“ Female”和“ VIP”

var genders = map[uint8]string{
    2: "Male",
    5: "Female",
}

var memberTypes = map[uint8]string{
    2: "Standard",
    5: "VIP",
}

或：

var genders = map[Gender]string{
    Male: "Male",
    Female: "Female",
}

var memberTypes = map[MemberType]string{
    Standard: "Standard",
    VIP: "VIP",
}

然后您将得到类似

 id := 5
 fmt.Println(genders[id]) // "Female"
 fmt.Println(memberTypes[id]) // "VIP"
 // or...
 fmt.Println(genders[Gender(id)]) // "Female"
 fmt.Println(memberTypes[MemberType(id)]) // "VIP"

Answer 3

根据godoc。在stringer

下有一个名为 golang.org/x/tools/cmd/stringer 的生成器。

使用 stringer ，您可以这样做。

/*enum.go*/

//go:generate stringer -type=Pill
type Pill int

const (
    Placebo Pill = iota
    Aspirin
    Ibuprofen
    Paracetamol
    Acetaminophen = Paracetamol
)

保存enum.go，然后运行go generate。纵梁将为您做好一切。

in the same directory will create the file pill_string.go, in package 
painkiller, containing a definition of

func (Pill) String() string

That method will translate the value of a Pill constant to the string
representation of the respective constant name, so that the call

fmt.Print(painkiller.Aspirin)

will print the string "Aspirin".

Answer 4

对于每种枚举类型，您都可以使用单独的方法来获取字符串像这样的值：-

package main

import (
    "fmt"
)

type Gender uint8
type MemberType uint8

const (
    Male     Gender     = 2
    Female   Gender     = 5
    Standard MemberType = 2
    VIP      MemberType = 5
)

func (data Gender) String() string {
    switch data {
    case Male:
        return "Male"
    case Female:
        return "Female"
    default:
        return "unknown"
    }
}

func (data MemberType) String() string {
    switch data {
    case Standard:
        return "Standard"
    case VIP:
        return "VIP"
    default:
        return "unknown"
    }
}

func main() {
    fmt.Println(Male.String())
    fmt.Println(Female.String())
    fmt.Println(VIP.String())
    fmt.Println(Standard.String())
}

游乐场网址：-https://play.golang.org/p/JIdXUC8BFML

如何在Golang中按值获取枚举变量名称？

4 个答案: