编辑代码

package main
import (
"errors
"fmt"
)
var errDo = errors.New("err do")

func do() error {
    return fmt.Errorf(" %w", errDo)
}

func main()[{
    if err := do(); errors.Is(err, errDo) {
        if err == errDo {
            fmt.Println("err == errDo")
        }else{
            fmt.Println("err is errDo")
        }
    }else{
        fmt.Println("err is not errDo")
    }

}