Golang操作結構體、Map轉化為JSON

結構體生成Json

package main import ( "encoding/json"
    "fmt" ) type IT struct { Company string `json:"-"` //此字段不會輸出到屏幕 //Company string `json:"company"` 這樣打印輸出別名首字母就會小寫(二次編碼)
    Subjects []string `json:"subjects"` //二次編碼
    IsOk     bool     `json:",string"` Price float64 `json:",string"` }
 func main() { //定義一個結構體變量，同時初始化
    s := IT{"itcast", []string{"Golang", "PHP", "Java", "C++"}, true, 666.666} //編碼，根據內容生成json文本 //buf, err := json.Marshal(s) //buf = {"subjects":["Golang","PHP","Java","C++"],"IsOk":"true","Price":"666.666"}
    buf, err := json.MarshalIndent(s, "", "    ") //格式化編碼
    if err != nil { fmt.Println("err = ", err) return } fmt.Println("buf = ", string(buf)) }

//結果
buf = { "subjects": [   //首字母小寫
               "Golang", "PHP", "Java", "C++" ], "IsOk": "true",   //string類型
       "Price": "666.666" }

Json轉成結構體

package main import ( "encoding/json"
    "fmt" ) type IT struct { Address string   `json:"address"` Languages []string `json:"languages"` //二次編碼
    Status    bool     `json:"isok"` Price float64 `json:"price"` } func main() { jsonBuf := ` { "address": "北京", "languages": [ "Golang", "PHP", "Java", "Python" ], "status": true, "price": 666.666 }` var tmp IT                                   //定義一個結構體變量
    err := json.Unmarshal([]byte(jsonBuf), &tmp) //第二個參數要地址傳遞
    if err != nil { fmt.Println("err = ", err) return } //fmt.Println("tmp = ", tmp)
    fmt.Printf("tmp = %+v\n", tmp) type IT2 struct { Subjects []string `json:"languages"` //二次編碼
 } var tmp2 IT2 err = json.Unmarshal([]byte(jsonBuf), &tmp2) //第二個參數要地址傳遞
    if err != nil { fmt.Println("err = ", err) return } fmt.Printf("tmp2 = %+v\n", tmp2) }

tmp = {Address:北京 Languages:[Golang PHP Java Python] Status:false Price:666.666} tmp2 = {Subjects:[Golang PHP Java Python]}

Map生成Json

package main import ( "encoding/json"
    "fmt" ) func main() { //創建一個map
    m := make(map[string]interface{}, 4) //因為類型多，可以用interface空接口
    m["address"] = "北京" m["languages"] = []string{"Golang", "PHP", "Java", "Python"} m["status"] = true m["price"] = 666.666

    //編碼成json //result, err := json.Marshal(m) //result = {"address":"北京","languages":["Golang","PHP","Java","Python"],"price":666.666,"status":true}
    result, err := json.MarshalIndent(m, "", "    ") if err != nil { fmt.Println("err = ", err) return } fmt.Println("result = ", string(result)) }

result = { "address": "北京", "languages": [ "Golang", "PHP", "Java", "Python" ], "price": 666.666, "status": true }

Json轉化為Map

package main import ( "encoding/json"
    "fmt" ) func main() { jsonBuf := ` { "company": "itcast", "subjects": [ "Go", "C++", "Python", "Test" ], "isok": true, "price": 666.666 }` //創建一個map
    m := make(map[string]interface{}, 4) err := json.Unmarshal([]byte(jsonBuf), &m) //第二個參數要地址傳遞
    if err != nil { fmt.Println("err = ", err) return } fmt.Printf("m = %+v\n", m) // var str string // str = string(m["company"]) //err， 無法轉換 // fmt.Println("str = ", str)

    var str string

    //類型斷言, 值，它是value類型
    for key, value := range m { //fmt.Printf("%v ============> %v\n", key, value)
        switch data := value.(type) { case string: str = data fmt.Printf("map[%s]的值類型為string, value = %s\n", key, str) case bool: fmt.Printf("map[%s]的值類型為bool, value = %v\n", key, data) case float64: fmt.Printf("map[%s]的值類型為float64, value = %f\n", key, data) case []string: fmt.Printf("map[%s]的值類型為[]string, value = %v\n", key, data) case []interface{}: fmt.Printf("map[%s]的值類型為[]interface, value = %v\n", key, data) } } }

map[address]的值類型為string, value = 北京 map[Languages]的值類型為[]interface, value = [Golang PHP Java Python] map[Status]的值類型為bool, value = true map[price]的值類型為float64, value = 666.666000

 實際項目中建議參考此鏈接博文：

https://www.kutu66.com//GitHub/article_108925#10-yfsys