How Golang defines error

How Golang defines error

During the development process, when the error content returned by the standard library could no longer meet our needs, we found builtin. error in go is an interface,

Related recommendations: golang tutorial

type error interface {
    Error() string
}

So you only need to create a structure containing the Error() string function.

1. Create a new errors package under go path

vim $GOPATH/github.com/mypractise/error/errors.go

package errors

type Error struct {
    ErrCode int
    ErrMsg  string
}

func NewError(code int, msg string) *Error {
    return &Error{ErrCode: code, ErrMsg: msg}
}

func (err *Error) Error() string {
    return err.ErrMsg
}

2. Start calling the errors package

vim ./test.go

package main

import (
    "encoding/json"
    "errors"
    "fmt"

    myerr "github.com/mypractise/errors"
)

func myErr() error {

    err := myerr.NewError(2, "err test")
    return err
}

func staErr() error {
    m := make(map[string]string)
    err := json.Unmarshal([]byte(""), m)
    if err != nil {
        return err
    }

    return errors.New("aaaaa")
}

func main() {
    err1 := staErr()
    fmt.Println("------sta err:", err1.Error())

    err2 := myErr()
    fmt.Println("------my err:", err2.Error(), err2.(*myerr.Error).ErrCode)
}

3. Run the test

go run ./test.go

PHP Chinese website , a large number of programming tutorials and website construction tutorials, welcome to learn.

The above is the detailed content of How Golang defines error. For more information, please follow other related articles on the PHP Chinese website!