Golang结构体字段遍历技巧

package main

import (
    "fmt"
    "reflect"
)

type User struct {
    Name string `json:"name"`
    Age  int    `json:"age"`
    City string `json:"city,omitempty"`
}

func main() {
    u := User{Name: "Alice", Age: 25, City: "Beijing"}

    t := reflect.TypeOf(u)
    v := reflect.ValueOf(u)

    for i := 0; i < t.NumField(); i++ {
        field := t.Field(i)
        value := v.Field(i)

        fmt.Printf("字段名: %s\n", field.Name)
        fmt.Printf("类型: %s\n", field.Type)
        fmt.Printf("值: %v\n", value.Interface())
        fmt.Printf("json 标签: %s\n", field.Tag.Get("json"))
        fmt.Println("---")
    }
}

u := &User{Name: "Bob"}
val := reflect.ValueOf(u).Elem() // 获取指针指向的元素

// 修改 Name 字段
nameField := val.FieldByName("Name")
if nameField.CanSet() {
    nameField.SetString("Charlie")
}

field, exists := t.FieldByName("City")
if exists {
    fmt.Println("找到字段:", field.Name)
    fmt.Println("标签:", field.Tag.Get("json"))
} else {
    fmt.Println("字段不存在")
}

func walkStruct(v reflect.Value, t reflect.Type) {
    for i := 0; i < v.NumField(); i++ {
        ft := t.Field(i)
        fv := v.Field(i)

        if ft.Type.Kind() == reflect.Struct {
            walkStruct(fv, ft.Type) // 递归进入
        } else {
            fmt.Printf("%s: %v\n", ft.Name, fv.Interface())
        }
    }
}