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如何实现遍历结构体字段? 好吧，言归正传!举个例子：
demo1:
package main
import (
"fmt"
"reflect"
)
type Student struct {
name string
age int
}
func main() {
v := reflect.ValueOf(Student{"乔峰", 29})
count := v.NumField()
for i := 0; i < count; i++ {
f := v.Field(i) //字段值
switch f.Kind() {
case reflect.String:
fmt.Println(f.String())
case reflect.Int:
fmt.Println(f.Int())
}
}
}
再举给栗子：
package main
import (
"fmt"
"reflect"
)
type LanType struct {
s1, s2, s3 string
}
var language interface{} = LanType{"Php", "Go", "Python3"}
func main() {
value := reflect.ValueOf(language)
for i := 0; i < value.NumField(); i++ {
fmt.Printf("字段索引 %d: %v\n", i, value.Field(i))
}
}
输出：
BASIC
字段索引 0: Php
字段索引 1: Go
字段索引 2: Python3
使用 for range遍历：
package main
import (
"fmt"
)
func main() {
language := []string{"Php", "Go", "Python3"}
for k, val := range language {
fmt.Printf("切片索引 %d is :%s\n", k, val)
}
}
输出：
BASIC
切片索引 0 is :Php
切片索引 1 is :Go
切片索引 2 is :Python3
package main
import (
"fmt"
)
func main() {
language := make(map[string]string)
language["1"] = "Php"
language["2"] = "Go"
language["3"] = "Python3"
language["4"] = "C#"
for key, val := range language {
fmt.Printf("%v=>%v\n", key, val)
}
}
输出：这里就不贴了，结果会随机输出，因为map遍历出来结果是无序的，顺序不好控制，也不利于业务逻辑;当业务依赖key次序时，那么我们就需要引入“sort”包来解决随机化问题：
比如这样：
package main
import (
"fmt"
"sort"
)
func main() {
language := make(map[string]string)
language["1"] = "Php"
language["2"] = "Go"
language["3"] = "Python3"
language["4"] = "C#"
sorted_keys := make([]string, 0)
for k, _ := range language {
sorted_keys = append(sorted_keys, k) // 提取键名
}
sort.Strings(sorted_keys) //
for _, k := range sorted_keys {
fmt.Printf("%v=>%v\n", k, language[k])
}
}
输出：
BASIC
1=>Php
2=>Go
3=>Python3
4=>C#
这样输出的结果运行多次也不会改变顺序。
package main
import (
"encoding/json"
"fmt"
)
//把结构体都改小写
type User struct {
UserName string `json:"user_name"` //json的tag标记
Nickname string `json:"nickname"`
Age int
Birthday string
Sex string
Email string
Phone string
}
func testStruct() {
user1 := &User{
UserName: "超哥",
Nickname: "大头哥",
Age: 18,
Birthday: "2008/8/8",
Sex: "男",
Email: "mahuateng@qq.com",
Phone: "110",
}
//开始json序列化
data, err := json.Marshal(user1)
if err != nil {
fmt.Printf("json.marshal failed,err:", err)
return
}
fmt.Printf("%s\n", string(data))
}
func testInt() {
var a = 18
//开始json序列化
data, err := json.Marshal(a)
if err != nil {
fmt.Printf("json.marshal failed,err:", err)
return
}
fmt.Printf("%s\n", string(data))
}
func testMap() {
var m map[string]interface{} //声明map
m = make(map[string]interface{}) //必须初始化map分配内存
m["username"] = "user1"
m["age"] = 18
m["sex"] = "man"
fmt.Println(m)
data, err := json.Marshal(m)
if err != nil {
fmt.Printf("json.marshal failed,err:", err)
return
}
fmt.Printf("%s\n", string(data))
}
func testSlice() {
//定义一个slice，元素是map
var m map[string]interface{}
var s []map[string]interface{}
m = make(map[string]interface{})
m["username"] = "user1"
m["age"] = 18
m["sex"] = "man"
s = append(s, m)
m = make(map[string]interface{})
m["username"]="user2"
m["age"]=188
m["sex"]="male"
s=append(s,m)
data, err := json.Marshal(s)
if err != nil {
fmt.Printf("json.marshal failed,err:", err)
return
}
fmt.Printf("%s\n", string(data))
}
func main() {
testStruct() //结构体的序列化
testInt()//序列化数值
testMap()//序列化map
testSlice()//序列化切片
}
