How can I create custom error types in Go?

How can I create custom error types in Go?

In Go, you can create custom error types by implementing the error interface. This involves defining a struct and a method that returns a string.

Can you show me an example of a custom error type?

Sure! Here's a simple example:

package main

import (
    "fmt"
)

type MyError struct {
    Message string
}

func (e *MyError) Error() string {
    return e.Message
}

func main() {
    err := &MyError{Message: "This is a custom error"}
    fmt.Println(err)
}

What are some use cases for custom errors?

Custom errors are useful for providing more context about an error, categorizing errors, or adding additional fields for debugging.

Can I wrap existing errors in my custom error type?

Yes, you can wrap existing errors by including them as a field in your custom error struct and implementing the Error() method to return both messages.