reflect.go

package main

import (
	"fmt"
	"reflect" // 这里引入reflect模块
)

type User struct {
	Name   string "user name" //这引号里面的就是tag
	Passwd string "user passsword"
}

func IsEmptyValue(v reflect.Value) bool {
	switch v.Kind() {
	case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
		return v.Len() == 0
	case reflect.Bool:
		return !v.Bool()
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		return v.Int() == 0
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
		return v.Uint() == 0
	case reflect.Float32, reflect.Float64:
		return v.Float() == 0
	case reflect.Interface, reflect.Ptr:
		return v.IsNil()
	}
	return false
}

func main() {
	user := new(User)
	user.Name = "Edge"
	//user.Passwd = "Tomorrow"

	v := reflect.TypeOf(user)

	fmt.Println(v)

	s := reflect.TypeOf(user).Elem() //通过反射获取type定义
	for i := 0; i < s.NumField(); i++ {
		fmt.Println(s.Field(i).Tag) //将tag输出出来
		fmt.Println(s.Field(i).Name)
		fmt.Println(s.Field(i).Index)
		value := reflect.ValueOf(user).Elem().Field(s.Field(i).Index[0])
		if IsEmptyValue(value) == false {
			fmt.Println(value)
		}
	}
}