Sets the optional parameters of the option

[zeroicey]

Set the default value. The required parameter should be changed to [Type]

[shadowspawn]

(Assuming you are talking about the example in the README...)

The example works fine with a required value of <type>?
Or does the comment not describe the behaviour very well, perhaps "specify the cheese topping"?

program
  .option('-c, --cheese <type>', 'add the specified type of cheese', 'blue');

https://github.com/tj/commander.js/blob/master/examples/options-defaults.js

[zeroicey]

I'm sorry That I didn't fully understand the role of <type>

There is nothing wrong with this program. It may be that my requirements are related to the optional parameters that cause unnecessary errors

I think when I use this option I can pass no arguments and use the default values

Excuse me. Have a nice day

[shadowspawn]

This option has a required value: -c, --cheese <type>. If the option is used then you must supply the value.

example
example -c blue
example -cblue
example --cheese blue
example --cheese=blue
example --cheese   <-- error, value not specified

This option has an optional value, it can be used just as a boolean flag or with a value: -c, --cheese [type]

example
example --cheese
example --cheese blue

[shadowspawn]

Closing this as resolved.

Feel free to open a new issue if it comes up again, with new information and renewed interest.