I am probably missing something really simple here:
package main
import (
"fmt"
"strconv"
"reflect"
)
func main() {
s := "abd"
fmt.Println(s)
_, err := strconv.Atoi(s)
if err != nil {
fmt.Println(err)
}
fmt.Println(reflect.TypeOf(err))
fmt.Println(err.Err)
}
I am trying to extract the error itself e.g. ErrSyntax or ErrRange, but I am not able to do so.
After looking at:
https://golang.org/src/strconv/atoi.go?s=3604:3671#L16
I see that err is a pointer to strconv.NumError
15 // A NumError records a failed conversion.
16 type NumError struct {
17 Func string // the failing function (ParseBool, ParseInt, ParseUint, ParseFloat)
18 Num string // the input
19 Err error // the reason the conversion failed (ErrRange, ErrSyntax)
20 }
And Err is the field that holds either ErrRange of ErrSyntax. Therefore, I thought that err.Err would work, but I get:
err.Err undefined (type error has no field or method Err
Err is public, am I missing something with visibility rules?
What am I missing?
Use a type assertion to get the *strconv.NumError value:
if e, ok := err.(*strconv.NumError); ok {
fmt.Println("e.Err", e.Err)
}