1.Map转JSON
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| package main import ( "encoding/json" "fmt" ) func main() { map1 := map[string]string { "name":"张三", "age":"18", "home":"北京", } 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) }
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2. Json转Map
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| package main import ( "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) }
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3.结构体转JSON
3.1 无字段标签
结构体转换成JSON
在开发中经常会用到。encoding/json
包是通过反射机制来实现编解码的,因此结构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。
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| package main import ( "encoding/json" "fmt" ) type Student struct { Name string Age int Class string phone string } 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) }
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3.2 有字段标签
json
包在解析结构体时,如果遇到key
为json
的字段标签,则会按照一定规则解析该标签。
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| package main import ( "encoding/json" "fmt" )
type Student struct { Name string `json:"_name"` Age int `json:"_age"` Class string `json:"-"` Phone string `json:"phone"` Score float32 } 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) }
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1.规则总结
- 有标签名时,标签名会作为
key
- 没有标签时,则会使用字段名。
- 有标签名时,但是标签名的值为
-
,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结构体的字段处理。
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| package main import ( "encoding/json" "fmt" ) type Student struct { Name string `json:"_name"` Age int `json:"_age"` Top } 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) }
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4.JSON转结构体
JSON
可以转换成结构体。同编码一样,json
包是通过反射机制来实现解码的,因此结构体必须导出所转换的字段,不导出的字段不会被json
包解析。另外解析时不区分大小写。
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| package main import ( "encoding/json" "fmt" ) type Student struct { Name string `json:"_name"` Age int `json:"_age"` Top } 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) }
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5.切片转JSON
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| package main import ( "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) }
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6.JSON转切片
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| package main import ( "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) }
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