Login to manage your account

Your email Please enter a valid email address.

Password Forgot Password?

Please enter a valid password.

OR

Don't have an account yet? Sign up

What does the error-first callback convention mean?

A The callback's first argument is an error object or null
B Errors must be thrown before the callback runs
C The callback only fires on error
D Errors are returned as the second argument

Answer

The callback's first argument is an error object or null

The signature (err, result) requires checking err before using the result. It predates promises and is still used across the core library.

All NodeJS MCQs

Login to manage your account

Your email id Please enter a valid email address.

Password Forgot Password?

Please enter a valid password.

OR

Don't have an account yet? Sign up as

Jobseeker

Employer