英文:
How to convert interface{} to []int?
问题
我正在使用Go编程语言进行编程。
假设有一个类型为interface{}的变量，其中包含一个整数数组。我该如何将interface{}转换回[]int类型？
我尝试了以下方法：
interface_variable.([]int)
但是我得到了以下错误：
panic: interface conversion: interface is []interface {}, not []int
英文:
I am programming in Go programming language.
Say there's a variable of type interface{} that contains an array of integers. How do I convert interface{} back to []int?
I have tried
interface_variable.([]int)
The error I got is:
panic: interface conversion: interface is []interface {}, not []int
答案1
得分: 15
这是一个[]interface{}而不仅仅是一个interface{}，你需要遍历它并进行转换：
2022年的解答
https://go.dev/play/p/yeihkfIZ90U
func ConvertSlice[E any](in []any) (out []E) {out = make([]E, 0, len(in))for _, v := range in {out = append(out, v.(E))}return}
go1.18之前的解答
http://play.golang.org/p/R441h4fVMw
func main() {a := []interface{}{1, 2, 3, 4, 5}b := make([]int, len(a))for i := range a {b[i] = a[i].(int)}fmt.Println(a, b)}
英文:
It's a []interface{} not just one interface{}, you have to loop through it and convert it:
the 2022 answer
https://go.dev/play/p/yeihkfIZ90U
func ConvertSlice[E any](in []any) (out []E) {out = make([]E, 0, len(in))for _, v := range in {out = append(out, v.(E))}return}
the pre-go1.18 answer
http://play.golang.org/p/R441h4fVMw
func main() {a := []interface{}{1, 2, 3, 4, 5}b := make([]int, len(a))for i := range a {b[i] = a[i].(int)}fmt.Println(a, b)}
答案2
得分: 2
正如其他人所说，你应该迭代切片并逐个转换对象。
最好在范围内使用类型开关以避免发生恐慌：
a := []interface{}{1, 2, 3, 4, 5}
b := make([]int, len(a))
for i, value := range a {
switch typedValue := value.(type) {
case int:
b[i] = typedValue
break
default:
fmt.Println("不是int类型：", value)
}
}
fmt.Println(a, b)
http://play.golang.org/p/Kbs3rbu2Rw
英文:
As others have said, you should iterate the slice and convert the objects one by one.
Is better to use a type switch inside the range in order to avoid panics:
a := []interface{}{1, 2, 3, 4, 5}b := make([]int, len(a))for i, value := range a {switch typedValue := value.(type) {case int:b[i] = typedValuebreakdefault:fmt.Println("Not an int: ", value)}}fmt.Println(a, b)
答案3
得分: 0
以下是翻译好的内容：
函数的返回值类型是interface{}，但实际返回的值是[]interface{}，所以请尝试使用以下代码：
func main() {values := returnValue.([]interface{})for i := range values {fmt.Println(values[i])}}
英文:
Func return value is interface{} but real return value is []interface{}, so try this instead:
func main() {values := returnValue.([]interface{})for i := range values {fmt.Println(values[i])}}
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论