使用Go不能在列表类型接口{}上作用范围

Question

Cannot Range Over List Type Interface {} In Function Using Go.

• for me is important then i execute for in a function.

How can fix?

package main

import (
    "fmt"
)

type MyBoxItem struct {
    Name string
}

type MyBox struct {
    Items []MyBoxItem
}

func (box *MyBox) AddItem(item MyBoxItem) []MyBoxItem {
    box.Items = append(box.Items, item)
    return box.Items
}

func PrintCustomArray(list interface{}) interface{}  {
    //items := reflect.ValueOf(list)
    for _, v := range list {
        fmt.Println(v.Key,v.Value)
    }
    return 0
}
func main() {

    items := []MyBoxItem{}
    item := MyBoxItem{Name: "Test Item 1"}
    box := MyBox{items}
    box.AddItem(item)
    fmt.Println((box.Items))
    PrintCustomArray(box.Items)
}

https://play.golang.org/p/ZcIBLMliq3

Error : cannot range over list (type interface {})

How can fix?

Answer 1

It's possible to implement PrintCustomArray using the reflect package, but most experienced Go programmers will write a simple for loop:

for _, i := range box.Items {
    fmt.Println("Name:", i.Name)
}

https://play.golang.org/p/RhubiCpry0

You can also encapsulate it in a function:

func PrintCustomArray(items []MyBoxItem) {
  for _, i := range items {
    fmt.Println("Name:", i.Name)
  }
}

https://play.golang.org/p/c4EPQIx1AH