How To Return Err In Golang

Go Programming

Returning errors in Golang is a fundamental aspect of writing robust and reliable code. As a Golang developer, I understand the importance of effectively handling errors to ensure the stability and maintainability of my applications. Let’s dive deep into the concept of returning errors in Golang and explore the best practices for error management.

Understanding Error Handling in Golang

In Golang, errors are represented by the built-in error interface. This interface is incredibly simple, consisting of just a single method:

type error interface {
Error() string

This method, Error(), returns a string that describes the error. By convention, if a function or method can return an error, it typically does so as the last return value. This allows the caller to inspect the error and take appropriate action based on its value.

Returning Errors

When writing functions or methods that may encounter errors, it’s crucial to return those errors to the calling code. This can be achieved using the return statement along with the error value:

func myFunction() error {
// ...
if err != nil {
return err
// ...
return nil

By returning errors explicitly, I ensure that the calling code can handle the error gracefully. This promotes a more robust and fault-tolerant application.

Creating Custom Errors

Sometimes, the built-in errors provided by Golang may not fully encapsulate the specific nature of an error in my code. In such cases, it’s beneficial to create custom error types using the errors package:

import "errors"

var ErrCustomError = errors.New("This is a custom error")

By defining custom errors, I can provide more context and clarity about the nature of the error, facilitating better error handling and debugging.

Best Practices for Error Management

When working with error handling in Golang, it’s essential to adhere to certain best practices to ensure code clarity and maintainability. Here are some practices that I find particularly helpful:

  • Handle Errors Where They Occur: It’s best to handle errors as close to their occurrence as possible. This makes the code easier to understand and maintain.
  • Use Error Wrapping: Golang 1.13 introduced the errors.Is and errors.As functions, which facilitate error wrapping and unwrapping. This allows for more informative error chains.
  • Provide Contextual Information: When creating custom errors, including contextual information about the error’s origin can greatly aid in troubleshooting and debugging.


Effectively returning errors in Golang is a critical part of producing high-quality, reliable code. By understanding the error interface, returning errors from functions, and following best practices for error management, I can ensure that my Golang applications are robust and stable even in the face of unexpected issues.