I don't seem to see a difference between paste/paste0 and str_c for combining a single vector into a single string, multiple strings into one string, or multiple vectors into a single string.
While I was writing the question I found this: https://www.rdocumentation.org/packages/stringr/versions/1.3.1/topics/str_c. The community example from richie@datacamp.com says the difference is is that str_c treats blanks as blanks (not as NAs) and recycles more appropriately. Any other differences?
paste0(..., collapse = NULL)is a wrapper for paste(..., sep = "", collapse = NULL), which means there is no separator. In other words, with paste0() you can not apply some sort of separator, while you do have that option with paste(), whereas a single space is the default.
str_c(..., sep = "", collapse = NULL) is equivalent to paste(), which means you do have the option to customize your desired separator. The difference is for str_c() the default is no separator, so it acts just like paste0() as a default.
Paste() and paste0() are both functions from the base package, whereas str_c() comes from the stringr package.
I did not test/microbenchmark it, but from my experience I do agree to Ryan str_c() is generally faster.
来源：https://stackoverflow.com/questions/50818932/what-is-the-difference-between-paste-paste0-and-str-c