Handling errors in Go - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the common way to handle errors in Go?

In Go, errors are handled by returning an error value from functions. You check if the error is not nil to see if something went wrong.

beginner

What does the error type represent in Go?

The error type is an interface in Go that represents an error condition with a single method Error() that returns a string describing the error.

beginner

How do you check if a function returned an error in Go?

You check if the returned error variable is not nil. If it is not nil, an error occurred and you can handle it accordingly.

intermediate

What is the purpose of the defer statement in error handling?

defer schedules a function call to run after the current function finishes. It is often used to clean up resources even if an error occurs.

intermediate

How can you create a custom error in Go?

You can create a custom error by using the errors.New() function or by defining a type that implements the error interface with an Error() method.

In Go, what does a function usually return to indicate an error?

A A string message

B A boolean true or false

C An error value of type error

D A panic

Functions return an error value of type error to indicate if something went wrong.

What should you check after calling a function that returns an error?

A If the error is zero

B If the error is nil

C If the error is empty string

D If the error is true

You check if the error is nil. If it is not nil, an error occurred.

Which Go statement helps ensure cleanup code runs even if an error occurs?

A defer

B goto

C panic

D return

defer schedules cleanup code to run after the function finishes.

How do you create a simple custom error message in Go?

A Using return nil

B Using fmt.Println("message")

C Using panic("message")

D Using errors.New("message")

Use errors.New("message") to create a new error with a custom message.

What does the Error() method return in a custom error type?

A A string describing the error

B An integer error code

C A boolean value

D Nothing

The Error() method returns a string describing the error.

Explain how error handling works in Go and why it is important to check errors after function calls.

Think about how Go functions return errors and what happens if you ignore them.

Describe how you can create and use a custom error type in Go.

Consider both simple and advanced ways to make your own error messages.