1.Map转JSON

package mainimport (    "encoding/json"    "fmt")func main()  {    // map外面    map1 := map[string]string {        "name":"张三",        "age":"18",        "home":"北京",    }    // 将map解析成json    json1, err := json.Marshal(map1)    if err != nil {        fmt.Println(err.Error())    }    fmt.Printf("json1: %s  类型: %T \n",json1,json1)      map2 := map[string][]string {        "fruit": {"香蕉","葡萄"},        "coder":{"PHP","Go","Java"},        "likes":{"打游戏","看动漫"},    }    json2, err := json.Marshal(map2)    if err != nil {        fmt.Println(err.Error())    }    fmt.Printf("json2: %s  类型: %T \n",json2,json2)}/**输入json1: {"age":"18","home":"北京","name":"张三"}  类型: []uint8 json2: {"coder":["PHP","Go","Java"],"fruit":["香蕉","葡萄"],"likes":["打游戏","看动漫"]}  类型: []uint8 */

2. Json转Map

package mainimport (    "encoding/json"    "fmt")func main()  {    json1 := `{"age":"18","home":"北京","name":"张三"}`    map1 := make(map[string]string)    err := json.Unmarshal([]byte(json1), &map1)    if err != nil {        fmt.Println(err.Error())    }    fmt.Printf("map1: %v T: %T\n",map1,map1)    json2 := `{"coder":["PHP","Go","Java"],"fruit":["香蕉","葡萄"],"likes":["打游戏","看动漫"]}`    map2 := make(map[string][]string)    err = json.Unmarshal([]byte(json2), &map2)    if err != nil {        fmt.Println(err.Error())    }    fmt.Printf("map2: %v T: %T\n",map2,map2)}/**输入map1: map[age:18 home:北京 name:张三] T: map[string]stringmap2: map[coder:[PHP Go Java] fruit:[香蕉 葡萄] likes:[打游戏 看动漫]] T: map[string][]string*/

3.构造体转JSON

3.1 无字段标签

构造体转换成JSON在开发中常常会用到。encoding/json包是通过反射机制来实现编解码的，<font color=red>因而构造体必须导出所转换的字段，没有导出的字段不会被encoding/json包解析。</font>

package mainimport (    "encoding/json"    "fmt")type Student struct {    Name string    Age int    Class string    phone string //小写字段，则不是会导出}func main()  {    s := Student{        Name:  "张三",        Age:   17,        Class: "三年级",        phone: "17600112222",    }    json1, err := json.Marshal(s)    if err != nil {        fmt.Println(err.Error())    }    fmt.Printf("json: %s \n",json1)}// 输入 json: {"Name":"张三","Age":17,"Class":"三年级"}

3.2 有字段标签

json包在解析构造体时，如果遇到key为JSON的字段标签，则会依照肯定规定解析该标签。

package mainimport (    "encoding/json"    "fmt")// 定义一个学生构造体type Student struct {    Name  string `json:"_name"` // 字段标签的语法    Age   int    `json:"_age"`    Class string `json:"-"` // 不解析    Phone string `json:"phone"`    Score float32 // 没有标签时，则用字段名}func main()  {    s := Student{        Name:  "张三",        Age:   17,        Class: "三年级",        Phone: "17600112222",        Score: 88.5,    }    json1, err := json.Marshal(s)    if err != nil {        fmt.Println(err.Error())    }    fmt.Printf("json: %s \n",json1)}// 输入-> json: {"_name":"张三","_age":17,"phone":"17600112222","Score":88.5}
1.规定总结
  • 有标签名时,标签名会作为key
  • 没有标签时,则会应用字段名。
  • 有标签名时，然而标签名的值为-，则不会导出

3.3 匿名字段

json包在解析匿名字段时，会将匿名字段的字段当成该构造体的字段解决。

package mainimport (    "encoding/json"    "fmt")type Student struct {    Name  string `json:"_name"`    Age   int    `json:"_age"`    Top // 匿名字段}type Top struct {    Sort int `json:"sort"`    Score float64    Class string}func main()  {    s := Student{        Name: "张三",        Age:  18,        Top:  Top{1,99.5,"一年级"},    }    json1, err := json.Marshal(s)    if err != nil {        fmt.Println(err.Error())    }    fmt.Printf("json: %s \n",json1)}//输入-> json: {"_name":"张三","_age":18,"sort":1,"Score":99.5,"Class":"一年级"}

4.JSON转构造体

JSON能够转换成构造体。同编码一样，json包是通过反射机制来实现解码的，因而构造体必须导出所转换的字段，不导出的字段不会被json包解析。另外解析时不辨别大小写。

package mainimport (    "encoding/json"    "fmt")type Student struct {    Name  string `json:"_name"`    Age   int    `json:"_age"`    Top // 匿名字段}type Top struct {    Sort int `json:"sort"`    Score float64    Class string}func main(){    student := Student{}    js := `{"_name":"张三","_age":18,"sort":1,"Score":99.5,"Class":"一年级"}`    err := json.Unmarshal([]byte(js), &student)    if err != nil {        fmt.Println(err.Error())    }    fmt.Printf("v: %+v  t: %T \n",student,student)}// 输入: v: {Name:张三 Age:18 Top:{Sort:1 Score:99.5 Class:一年级}}  t: main.Student

5.切片转JSON

package mainimport (    "encoding/json"    "fmt")func main(){    student := []string {        "张三",        "李四",        "小米",    }    marshal, err := json.Marshal(student)    if err != nil {        fmt.Println(err.Error())    }    fmt.Printf("v :%s T:%T",marshal,marshal)}// 输入 v :["张三","李四","小米"] T:[]uint8

6.JSON转切片

package mainimport (    "encoding/json"    "fmt")func main(){    json1 := `["张三","李四","小米"]`    var sc []string    err := json.Unmarshal([]byte(json1), &sc)    if err != nil {        fmt.Println(err.Error())    }    fmt.Printf("v :%v T:%T",sc,sc)}// 输入: v :[张三 李四 小米] T:[]string

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