Go检查结构体中是否存在某个字段及创建结构体切片或映射

package main
import (
	"log"
	"reflect"
)
func main() {
	type test struct {
		A bool
		B bool
		C bool
	}
	v := new(test)
	metaValue := reflect.ValueOf(v).Elem()
	for _, name := range []string{"A", "C", "Z"} {
		field := metaValue.FieldByName(name)
		if field == (reflect.Value{}) {
			log.Printf("Field %s not exist in struct", name)
		}
	}
}

package main
import (
	"fmt"
)
type Widget struct {
	id    int
	attrs []string
}
func main() {
	widgets := []Widget{
		Widget{
			id:    10,
			attrs: []string{"blah", "foo"},
		},
		Widget{
			id:    11,
			attrs: []string{"foo", "bar"},
		},
		Widget{
			id:    12,
			attrs: []string{"xyz"},
		},
	}
	for _, j := range widgets {
		fmt.Printf("%d ", j.id)
		for _, y := range j.attrs {
			fmt.Printf(" %s ", y)
		}
		fmt.Println()
	}
}

package main

import "fmt"

type Emp struct {
	x int
	y []string
}

func main() {
	var list = map[string]*Emp{"e1": {1001, []string{"John", "US"}}}

	e := new(Emp)
	e.x = 1002
	e.y = []string{"Rock", "UK"}

	list["e2"] = e

	fmt.Println(list["e1"])
	fmt.Println(list["e2"])
}