v := "hello"
t := reflect.TypeOf(v)      // 返回 reflect.Type
val := reflect.ValueOf(v)   // 返回 reflect.Value

fmt.Println(t)        // string
fmt.Println(val.Kind()) // string

func handleDynamicValue(i interface{}) {
    v := reflect.ValueOf(i)
    switch v.Kind() {
    case reflect.String:
        fmt.Println("字符串:", v.String())
    case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
        fmt.Println("整数:", v.Int())
    case reflect.Float32, reflect.Float64:
        fmt.Println("浮点数:", v.Float())
    case reflect.Bool:
        fmt.Println("布尔值:", v.Bool())
    case reflect.Slice:
        fmt.Println("切片，长度:", v.Len())
        for i := 0; i < v.Len(); i++ {
            fmt.Printf("  [%d] = %v\n", i, v.Index(i).Interface())
        }
    case reflect.Struct:
        fmt.Println("结构体，字段数:", v.NumField())
        for i := 0; i < v.NumField(); i++ {
            field := v.Field(i)
            fmt.Printf("  字段%d: %v\n", i, field.Interface())
        }
    default:
        fmt.Println("不支持的类型")
    }
}

func setStringValue(ptr interface{}) {
    v := reflect.ValueOf(ptr)
    if v.Kind() != reflect.Ptr || !v.Elem().CanSet() {
        fmt.Println("需要传入可设置的指针")
        return
    }
    elem := v.Elem()
    if elem.Kind() == reflect.String {
        elem.SetString("已修改")
    }
}

// 调用
s := "原始"
setStringValue(&s)
fmt.Println(s) // 输出：已修改

type User struct {
    Name string `json:"name" validate:"required"`
    Age  int    `json:"age"`
}

func parseTags(obj interface{}) {
    t := reflect.TypeOf(obj)
    for i := 0; i < t.NumField(); i++ {
        field := t.Field(i)
        jsonTag := field.Tag.Get("json")
        validateTag := field.Tag.Get("validate")
        fmt.Printf("字段: %s, json tag: %s, validate: %s\n",
            field.Name, jsonTag, validateTag)
    }
}