Swift Document

For function documentation
https://docs.swift.org/swift-book/LanguageGuide/Functions.html

Where and what is written in the Swift document? I think there are methods but there are no functions.

Almost all programming languages have the same method and function.(There may be differences between member functions and non-member functions, but there is no difference in nature.) Therefore, it is not clear to the respondents what they are asking in this question.In such a place where technicians gather, you need to have the skills to write questions that you want to answer.