How to convert a vector of strings to Title Case

Question

I have a vector of strings in lower case. I\'d like to change them to title case, meaning the first letter of every word would be capitalized. I\'ve managed to do it with a

Answer 1

The main problem is that you're missing perl=TRUE (and your regex is slightly wrong, although that may be a result of flailing around to try to fix the first problem).

Using [:lower:] instead of [a-z] is slightly safer in case your code ends up being run in some weird (sorry, Estonians) locale where z is not the last letter of the alphabet ...

re_from <- "\\b([[:lower:]])([[:lower:]]+)"
strings <- c("first phrase", "another phrase to convert",
             "and here's another one", "last-one")
gsub(re_from, "\\U\\1\\L\\2" ,strings, perl=TRUE)
## [1] "First Phrase"              "Another Phrase To Convert"
## [3] "And Here's Another One"    "Last-One"    

You may prefer to use \\E (stop capitalization) rather than \\L (start lowercase), depending on what rules you want to follow, e.g.:

string2 <- "using AIC for model selection"
gsub(re_from, "\\U\\1\\E\\2" ,string2, perl=TRUE)
## [1] "Using AIC For Model Selection"