go语言解析 map[string]interface{} 数据格式

注意事项

• map记得分配内存
• 解析出来的int类型会变成float64类型
• 注意判断不为nil后再转换类型

package main

import (
    "fmt"
    "encoding/json"
)

func main() {
    var m map[string]interface{}    //声明变量，不分配内存
    m = make(map[string]interface{}) //必可不少，分配内存
    m["name"] = "simon"
    var age int = 12
    m["age"] = age
    m["addr"] = "China"
    print_map(m)
    fmt.Println()

    data, err:=json.Marshal(m)
    fmt.Println("err:", err)
    fmt.Println(data)
    fmt.Println()

    m1 := make(map[string]interface{})
    err = json.Unmarshal(data, &m1)
    fmt.Println("err:", err)
    fmt.Println(m1)
    print_map(m1)
    fmt.Println()

    if m1["name"]!= nil {
        fmt.Println(m1["name"].(string))
    }
    if m1["type"]!= nil {
        fmt.Println(m1["type"].(string))
    } else {
        fmt.Println("there is not the key of type")
    }

}

//解析 map[string]interface{} 数据格式
func print_map(m map[string]interface{}) {
    for k, v := range m {
        switch value := v.(type) {
        case nil:
            fmt.Println(k, "is nil", "null")
        case string:
            fmt.Println(k, "is string", value)
        case int:
            fmt.Println(k, "is int", value)
        case float64:
            fmt.Println(k, "is float64", value)
        case []interface{}:
            fmt.Println(k, "is an array:")
            for i, u := range value {
                fmt.Println(i, u)
            }
        case map[string]interface{}:
            fmt.Println(k, "is an map:")
            print_map(value)
        default:
            fmt.Println(k, "is unknown type", fmt.Sprintf("%T", v))
        }
    }
}

运行结果

name is string simon
age is int 12
addr is string China

err: 
[123 34 97 100 100 114 34 58 34 67 104 105 110 97 34 44 34 97 103 101 34 58 49 50 44 34 110 97 109 101 34 58 34 115 105 109 111 110 34 125]

err: 
map[addr:China age:12 name:simon]
name is string simon
addr is string China
age is float64 12

simon
there is not the key of type

Process finished with exit code 0