Go类型断言demo
package main
import (
"bytes"
"encoding/json"
"fmt"
"io"
"net/http"
"time"
"github.com/unknwon/com"
)
//空接口
func test1() {
a := make(map[string]interface{}, 20)
a["name"] = "haha"
a["age"] = 20
a["merried"] = true
a["hobby"] = []string{"喝", "跳", "rap"}
fmt.Printf("type:%T v:%#v
", a["hobby"],a["hobby"])
v,ok := a["hobby"].([]string)
if(!ok){
fmt.Println("type is not map.") //type:[]string v:[]string{"喝", "跳", "rap"}
}
fmt.Println(v[0]) //喝
}
//接口作为函数的参数
func test2(a interface{}) {
fmt.Printf("type:%T value:%v
", a, a)
}
type resParamData struct {
Code int `json:"code"`
Msg string `json:"Msg"`
Data interface{} //方法一
}
type userinfo struct {
Name string `json:"name"`
Age int `json:"age"`
}
func test3() {
var m = make(map[string]interface{}, 0)
m["name"] = "test"
m["age"] = 20
var res resParamData
res.Code = 200
res.Msg = "ok"
res.Data = m
fmt.Println(res.Data)
value, ok := res.Data.(map[string]interface{})
if !ok {
fmt.Println("It's not ok for type Order")
return
}
fmt.Println("The value is ", value["name"])
fmt.Println("The value is ", value["age"])
fmt.Printf("type:%T value:%v
", value["age"], value["age"])
}
func test4() {
var uinfo = userinfo{
Name: "lisi",
Age: 18,
}
var resdata resParamData
resdata.Code = 200
resdata.Msg ="ok"
resdata.Data = uinfo
fmt.Println(resdata.Data)
value, ok := resdata.Data.(userinfo)
if !ok {
fmt.Println("It's not ok for type Order")
return
}
fmt.Println("The value is ", value.Name)
fmt.Println("The value is ", value.Age)
fmt.Printf("type:%T value:%v
", value.Name, value.Name)
fmt.Printf("type:%T value:%v
", value.Age, value.Age)
}
type PostresData2 struct {
Data interface{} //方法一
Errmsg string `json:"errmsg"`
Errno int `json:"errno"`
}
func test5() {
var d PostresData2
url := "https://api.ibanana.club/select/major/list_by_key?page=1&row=10&major_name=工程"
res := SetGet(url)
_ = json.Unmarshal([]byte(res), &d)
fmt.Println(1111111111)
fmt.Printf("type:%T value:%#v
", d, d)
fmt.Printf("type:%T value:%#v
", d.Errno, d.Errno)
fmt.Printf("type:%T value:%#v
", d.Data, d.Data)
value,ok:=d.Data.([]interface {})
if !ok {
fmt.Println("It's not ok for type major")
return
}
for _,v:=range value{
m,ok:=v.(map[string]interface {})
if !ok {
fmt.Println("It's not ok for type m")
return
}
id:=com.StrTo(com.ToStr(m["id"])).MustInt64()
fmt.Printf("type:%T value:%v
",id, id) //type:int64 value:20
fmt.Printf("type:%T value:%v
", m["major_name"], m["major_name"]) //type:string value:交通工程
//改变期值
if(id==19){
m["id"]=100
m["major_name"]="edit value22"
}
}
fmt.Println("GetTest")
fmt.Println(d)
//httpext.SuccessExt(ctx, d)
}
func main() {
//test5()
//test4()
//test3()
test1()
//a := 12
//test2(a)
//test2(nil)
//test2(false)
}
// Get ... 发送请求 ...
// url： 请求地址
// response： 请求返回的内容
func SetGet(url string) string {
// 超时时间：5秒
client := &http.Client{Timeout: 5 * time.Second}
resp, err := client.Get(url)
if err != nil {
panic(err)
}
defer resp.Body.Close()
var buffer [512]byte
result := bytes.NewBuffer(nil)
for {
n, err := resp.Body.Read(buffer[0:])
result.Write(buffer[0:n])
if err != nil && err == io.EOF {
break
} else if err != nil {
panic(err)
}
}
return result.String()
}
test5接口的反参
{
"code": 200,
"data": {
"Data": [
{
"id": 100,
"major_name": "edit value22"
},
{
"id": 20,
"major_name": "交通工程"
},
{
"id": 22,
"major_name": "交通管理工程"
},
{
"id": 23,
"major_name": "交通设备与控制工程"
},
{
"id": 46,
"major_name": "信息工程"
},
{
"id": 50,
"major_name": "假肢矫形工程"
},
{
"id": 53,
"major_name": "光电信息科学与工程"
},
{
"id": 63,
"major_name": "农业工程"
},
{
"id": 64,
"major_name": "农业建筑环境与能源工程"
},
{
"id": 66,
"major_name": "农业水利工程"
}
],
"errmsg": "ok",
"errno": 200
},
"msg": "ok"
}