Reflection.Value的字符串方法无法按预期工作

Question

I'm trying to retrieve the string value from a reflect.Value,

I expect value.String() to be okok but I got <interface {} Value> instead.

Did I miss something?

package main

import (
    "fmt"
    "reflect"
)

func dump(args *[]interface{}) {
    value := reflect.ValueOf(*args).Index(0)
    fmt.Println(value.String())
    if value.String() != "okok" {
        fmt.Println("miss")
    }
}

func main () {
    var args []interface{}
    args = append(args, "okok")
    dump(&args)
}

Answer 1

The documentation for Value.String explains the behavior:

Unlike the other getters, it does not panic if v's Kind is not String. Instead, it returns a string of the form "<T value>" where T is v's type.

String is just an implementation of the fmt.Stringer interface.

If you want the value itself, you can use the Interface function on reflect.Value and then do a type assertion to get the string. Example:

package main

import (
    "fmt"
    "reflect"
)

func dump(args *[]interface{}) {
    value := reflect.ValueOf(*args).Index(0)
    str := value.Interface().(string)
    fmt.Println(str)
    if str != "okok" {
        fmt.Println("miss")
    }
}

func main() {
    var args []interface{}
    args = append(args, "okok")
    dump(&args)
}

Playground link