JSON 语法是 JavaScript 语法的子集。JSON 语法是 JavaScript 对象表示法语法的子集。
数据在名称/值对中
数据由逗号分隔
大括号保存对象
中括号保存数组
1.JSON名称/值对
"name" : "value"
2.JSON值
可以是:
数字(整数或浮点数) 字符串(在双引号中) 逻辑值(true 或 false) 数组(在中括号中) 对象(在大括号中) null
JSON数据
JSON 数字可以是整型或者浮点型
{ "age":30 }
JSON对象
JSON 对象在大括号({})中书写:
对象可以包含多个名称/值对:
{ "name": "runoob", "alexa": 10000, "sites": { "site1": "www.runoob.com", "site2": "m.runoob.com", "site3": "c.runoob.com" } }
JSON数组
JSON 数组在中括号中书写:
数组可包含多个对象
{ "sites": [ { "name": "菜鸟教程", "url": "www.runoob.com" }, { "name": "google", "url": "www.google.com" }, { "name": "微博", "url": "www.weibo.com" } ] }
- JSON布尔值
{ "flag":true }
- JSON null
{ "runoob":null }
Json解析到结构体
package main import ( "encoding/json" "fmt" ) type Server struct { ServerName string ServerIP string } type Serverslice struct { Servers []Server } func main() { var s Serverslice str := `{"servers": [{"serverName":"Guangzhou_Base","serverIP":"127.0.0.1"}, {"serverName":"Beijing_Base","serverIP":"127.0.0.2"}]}` err := json.Unmarshal([]byte(str), &s) if err != nil { fmt.Println(err) } fmt.Println(s) fmt.Println(s.Servers[0].ServerName) }
输出:
{[{Guangzhou_Base 127.0.0.1} {Beijing_Base 127.0.0.2}]}
Guangzhou_Base
示例二:
package main import ( "encoding/json" "fmt" ) type Server struct { ServerName string `json:"serverName"` ServerIP string `json:"serverIP"` } type Serverslice struct { Servers []Server `json:"servers"` } func main() { var s Serverslice str := `{"servers": [{"serverName":"Guangzhou_Base","serverIP":"127.0.0.1"}, {"serverName":"Beijing_Base","serverIP":"127.0.0.2"}]}` err := json.Unmarshal([]byte(str), &s) if err != nil { fmt.Println(err) } fmt.Println(s) fmt.Println(s.Servers[0].ServerName) s.Servers[0].ServerIP = "192.168.6.4" data, err := json.Marshal(s) if err != nil { fmt.Println(err) return } else { fmt.Println(string(data)) } }
输出:
{[{Guangzhou_Base 127.0.0.1} {Beijing_Base 127.0.0.2}]}
Guangzhou_Base
{"servers":[{"serverName":"Guangzhou_Base","serverIP":"192.168.6.4"},{"serverName":"Beijing_Base","serverIP":"127.0.0.2"}]}
二、JSON转map
package main import ( "fmt" "encoding/json" ) func main() { b := []byte(`{"IP": "127.0.0.1", "name": "SKY"}`) m := make(map[string]string) err := json.Unmarshal(b, &m) if err != nil { fmt.Println("Umarshal failed:", err) return } fmt.Println("m:", m) for k,v :=range m { fmt.Println(k, ":", v) } }
输出:
m: map[IP:127.0.0.1 name:SKY] IP : 127.0.0.1 name : SKY
生成JSON
package main import ( "encoding/json" "fmt" ) type Server struct { ServerName string `json:"serverName,string"` ServerIP string `json:"serverIP,omitempty"` } type Serverslice struct { Servers []Server `json:"servers"` } func main() { var s Serverslice s.Servers = append(s.Servers, Server{ServerName: "Guangzhou_Base", ServerIP: "127.0.0.1"}) s.Servers = append(s.Servers, Server{ServerName: "Shenzhen_Base", ServerIP: "127.0.0.2"}) s.Servers = append(s.Servers, Server{ServerName: "Beijing_Base", ServerIP: ""}) b, err := json.Marshal(s) if err != nil { fmt.Println("JSON ERR:", err) } fmt.Println(string(b)) }
输出:
{"servers":[{"serverName":""Guangzhou_Base"","serverIP":"127.0.0.1"},{"serverName":""Shenzhen_Base"","serverIP":"127.0.0.2"},{"serverName":""Beijing_Base""}]}