英文:
How to pass interface pointer through a function in Golang?
问题
我正在测试golang的功能，并遇到了一个概念，即我可以使用接口的指针作为接口本身。在下面的代码中，我该如何确保one的值变为random。
package main
import (
"fmt"
)
func some(check interface{}) {
check = "random"
}
func main() {
var one *interface{}
some(one)
fmt.Println(one)
}
具体来说，我需要知道如何将接口指针传递给一个接受接口作为参数的函数。
谢谢！
英文:
I was testing golang functionalities and came across this concept where I can use a pointer of an interface as an interface itself. In the below code, how do I ensure that the value of one changes to random.
package main
import (
"fmt"
)
func some(check interface{}) {
check = "random"
}
func main() {
var one *interface{}
some(one)
fmt.Println(one)
}
Specifically, I need ways in which I can pass an interface pointer to a function which accepts an interface as an argument.
Thanks!
答案1
得分: 12
- 将
interface{}的指针作为some的第一个参数接受。 - 将
one的地址传递给some。
package main
import (
"fmt"
)
func some(check *interface{}) {
*check = "random"
}
func main() {
var one interface{}
some(&one)
fmt.Println(one)
}
如果你想保持some的相同签名，你将需要使用reflect包来设置interface{}指针的值：
package main
import (
"fmt"
"reflect"
)
func some(check interface{}) {
val := reflect.ValueOf(check)
if val.Kind() != reflect.Ptr {
panic("some: check must be a pointer")
}
val.Elem().Set(reflect.ValueOf("random"))
}
func main() {
var one interface{}
some(&one)
fmt.Println(one)
}
注意：如果传递的值不能赋值给check指向的类型，val.Elem().Set()会引发恐慌。
英文:
- Accept a pointer to
interface{}as the first parameter tosome - Pass the address of
onetosome
<!-- -->
package main
import (
"fmt"
)
func some(check *interface{}) {
*check = "random"
}
func main() {
var one interface{}
some(&one)
fmt.Println(one)
}
https://play.golang.org/p/ksz6d4p2f0
If you want to keep the same signature of some, you will have to use the reflect package to set the interface{} pointer value:
package main
import (
"fmt"
"reflect"
)
func some(check interface{}) {
val := reflect.ValueOf(check)
if val.Kind() != reflect.Ptr {
panic("some: check must be a pointer")
}
val.Elem().Set(reflect.ValueOf("random"))
}
func main() {
var one interface{}
some(&one)
fmt.Println(one)
}
https://play.golang.org/p/ocqkeLdFLu
Note: val.Elem().Set() will panic if the value passed is not assignable to check's pointed-to type.
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