Implement custom error types in Golang

Creating custom error types in Go provides more detailed error messages. Create a custom error type: Use the error interface to define the error type, and implement the Error() method to return the error message. Use custom error types: Use custom error types like any other error type. Practical example: File read operation uses a custom error type to provide details of an unreadable file path. Benefits: more specific messages, higher maintainability, differentiated handling of different errors.

Implementing custom error types in Go

Introduction

Error handling A vital part of software development, Go provides a powerful mechanism to create custom error types to provide more specific and meaningful error messages.

Create a custom error type

To create a custom error type in Go, you can use the error interface:

type MyError struct {
    msg string
}

// 实现 error 接口的 Error 方法
func (e MyError) Error() string {
    return e.msg
}

## The

#MyError type implements the Error() method, which returns an error message.

Using Custom Error Types

Once you create a custom error type, you can use it like any other error type:

func foo() error {
    return MyError{"Custom error message"}
}

Practical case

The following is a practical example of using a custom error type:

File read operation:

package main

import (
    "fmt"
    "io/ioutil"
)

type FileReadError struct {
    path string
    err  error
}

func (e FileReadError) Error() string {
    return fmt.Sprintf("Could not read file '%s': %v", e.path, e.err)
}

func main() {
    content, err := ioutil.ReadFile("myfile.txt")
    if err != nil {
        return fmt.Errorf("ReadFile error: %w", FileReadError{path: "myfile.txt", err: err})
    }
}

By using a custom error type

FileReadError, we can provide a more detailed error message, including the file path that cannot be read.

Benefits

Using custom error types has the following benefits:

Provide more specific and meaningful error messages
• Improve code maintainability and readability
• Allow different types of errors to be handled differently

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