When there are multiple optional parameters (e.g. 3), how to specify e.g. the 3rd one (skip 1st and 2nd optional params)?

[antermin]

For example:
/youtube/charts/:category?/:country?/:embed?

category, country and embed are optional, and let's say I want to specify the value of embed and use default values for other optional parameters.

What URL / route should I use?

I have tried several times but I couldn't figure out the correct way to skip the 1st and 2nd params.

e.g. These won't work:
https://rsshub.app/youtube/charts/:/:/no
https://rsshub.app/youtube/charts/?/?/no
https://rsshub.app/youtube/charts/default/default/no
https://rsshub.app/youtube/charts/no

[TonyRL]

You can't skip the first and the second optional parameter when specifying the third parameter. A parameter that is optional means it has a default value if you don't provide one. Usually the default value is also mentioned in the docs.

[antermin]

A follow-up question:

I noticed that the X / Twitter route can use another format to specify some options:
https://rsshub.app/twitter/user/durov/readable=1&authorNameBold=1 ...

Suppose I want to improve the Mercari route so that it can accept more search options (#18823). If the normal format is used, it may result in something like:
/mercari/:sort/:order/:status/:keyword/:brandids?/:categoryids?/:minprice?/:maxprice?/:exclkeywords?

This is long and the user has to fill in the default values of 1st - 4th optional parameters if they want to use e.g. exclkeywords.

Is it a good idea to use the another format so that it can look like /mercari/create_time/desc/default/KEYWORD/exclkeywords=KEYWORDS_TO_EXCLUDE (versus something like /mercari/create_time/desc/default/KEYWORD/all/all/0/9999999/KEYWORDS_TO_EXCLUDE)?

[wrobelda]

Is there a reason why a router/parameterA//parameterC URL (with extra flashes whenever parameter is missing) could not be supported? RSSHub clearly recognizes such an URL as distinct from the router/parameterA/parameterC. I am a noob when it comes to Node.JS, though, so hopefully this is not a dumb question.