how to fix this error TypeError [ERR_INVALID_CALLBACK]: Callback must be a function

Question

I am a beginner to the nodejs. When I type the below, the code error occurs like this:

TypeError [ERR_INVALID_CALLBACK]: Callback must be a function

Answer 1

fs.writeFile(...) requires a third (or fourth) parameter which is a callback function to be invoked when the operation completes. You should either provide a callback function or use fs.writeFileSync(...)

See node fs docs for more info.