range over interface{} 存储切片 [英] range over interface{} which stores a slice

问题描述

假设您有一个接受 t interface{} 的函数.如果确定 t 是一个切片，我如何在该切片上range?

Given the scenario where you have a function which accepts t interface{}. If it is determined that the t is a slice, how do I range over that slice?

func main() {
    data := []string{"one","two","three"}
    test(data)
    moredata := []int{1,2,3}
    test(data)
}

func test(t interface{}) {
    switch reflect.TypeOf(t).Kind() {
    case reflect.Slice:
        // how do I iterate here?
        for _,value := range t {
            fmt.Println(value)
        }
    }
}

Go Playground 示例:http://play.golang.org/p/DNldAlNShB

Go Playground Example: http://play.golang.org/p/DNldAlNShB

推荐答案

嗯，我用了 reflect.ValueOf 然后如果它是一个切片你可以调用 Len()和 Index() 在值上获取切片的 len 和索引处的元素.我认为您无法使用范围操作来执行此操作.

Well I used reflect.ValueOf and then if it is a slice you can call Len() and Index() on the value to get the len of the slice and element at an index. I don't think you will be able to use the range operate to do this.

package main

import "fmt"
import "reflect"

func main() {
    data := []string{"one","two","three"}
    test(data)
    moredata := []int{1,2,3}
    test(moredata)
} 

func test(t interface{}) {
    switch reflect.TypeOf(t).Kind() {
    case reflect.Slice:
        s := reflect.ValueOf(t)

        for i := 0; i < s.Len(); i++ {
            fmt.Println(s.Index(i))
        }
    }
}

Go Playground 示例:http://play.golang.org/p/gQhCTiwPAq

Go Playground Example: http://play.golang.org/p/gQhCTiwPAq

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