变量声明后转到字符串

Question

看看在here发现的这个片段

import (
    "encoding/xml"
    "fmt"
    "os"
)

func main() {
    type Address struct {
        City, State string
    }
    type Person struct {
        XMLName   xml.Name `xml:"person"`
        Id        int      `xml:"id,attr"`
        FirstName string   `xml:"name>first"`
        LastName  string   `xml:"name>last"`
        Age       int      `xml:"age"`
        Height    float32  `xml:"height,omitempty"`
        Married   bool
        Address
        Comment string `xml:",comment"`
    }

    v := &Person{Id: 13, FirstName: "John", LastName: "Doe", Age: 42}
    v.Comment = " Need more details. "
    v.Address = Address{"Hanga Roa", "Easter Island"}

    enc := xml.NewEncoder(os.Stdout)
    enc.Indent("  ", "    ")
    if err := enc.Encode(v); err != nil {
        fmt.Printf("error: %v\n", err)
    }

}

我可以理解在struct Person，它有一个名为Id的var，它是int类型，但是这个东西怎么样

xml:"person" 

after int? What does it mean? Thanks.

Answer 1

它是一个struct标签。库使用这些来为带有额外信息的结构域注释;在这种情况下，模块encoding/xml使用这些struct标签来表示哪些标签对应于struct字段。

Answer 2

这意味着该变量将出现在Person示例的名称中

type sample struct {
     dateofbirth string `xml:"dob"`
}

In the above example, the field 'dateofbirth' will present in the name of 'dob' in the XML.

你会在go结构中经常看到这种符号。