Capitalize the first letter of both words in a two word string

问题

Let's say that I have a two word string and I want to capitalize both of them.

name <- c("zip code", "state", "final count")

The Hmisc package has a function capitalize which capitalized the first word, but I'm not sure how to get the second word capitalized. The help page for capitalize doesn't suggest that it can perform that task.

library(Hmisc)
capitalize(name)
# [1] "Zip code"    "State"       "Final count"

I want to get:

c("Zip Code", "State", "Final Count")

What about three-word strings:

name2 <- c("I like pizza")

回答1:

The base R function to perform capitalization is toupper(x). From the help file for ?toupper there is this function that does what you need:

simpleCap <- function(x) {
  s <- strsplit(x, " ")[[1]]
  paste(toupper(substring(s, 1,1)), substring(s, 2),
      sep="", collapse=" ")
}

name <- c("zip code", "state", "final count")

sapply(name, simpleCap)

     zip code         state   final count 
   "Zip Code"       "State" "Final Count"

Edit This works for any string, regardless of word count:

simpleCap("I like pizza a lot")
[1] "I Like Pizza A Lot"

回答2:

There is a build-in base-R solution for title case as well:

tools::toTitleCase("demonstrating the title case")
## [1] "Demonstrating the Title Case"

library(tools)
toTitleCase("demonstrating the title case")
## [1] "Demonstrating the Title Case"

回答3:

Match a regular expression that starts at the beginning ^ or after a space [[:space:]] and is followed by an alphabetical character [[:alpha:]]. Globally (the g in gsub) replace all such occurrences with the matched beginning or space and the upper-case version of the matched alphabetical character, \\1\\U\\2. This has to be done with perl-style regular expression matching.

gsub("(^|[[:space:]])([[:alpha:]])", "\\1\\U\\2", name, perl=TRUE)
# [1] "Zip Code"    "State"       "Final Count"

In a little more detail for the replacement argument to gsub(), \\1 says 'use the part of x matching the first sub-expression', i.e., the part of x matching (^|[[:spacde:]]). Likewise, \\2 says use the part of x matching the second sub-expression ([[:alpha:]]). The \\U is syntax enabled by using perl=TRUE, and means to make the next character Upper-case. So for "Zip code", \\1 is "Zip", \\2 is "code", \\U\\2 is "Code", and \\1\\U\\2 is "Zip Code".

The ?regexp page is helpful for understanding regular expressions, ?gsub for putting things together.

回答4:

Use this function from stringi package

stri_trans_totitle(c("zip code", "state", "final count"))
## [1] "Zip Code"      "State"       "Final Count" 

stri_trans_totitle("i like pizza very much")
## [1] "I Like Pizza Very Much"

回答5:

Alternative:

library(stringr)
a = c("capitalise this", "and this")
a
[1] "capitalise this" "and this"       
str_to_title(a)
[1] "Capitalise This" "And This"

回答6:

Try:

require(Hmisc)
sapply(name, function(x) {
  paste(sapply(strsplit(x, ' '), capitalize), collapse=' ')
})

回答7:

From the help page for ?toupper:

.simpleCap <- function(x) {
    s <- strsplit(x, " ")[[1]]
    paste(toupper(substring(s, 1,1)), substring(s, 2),
          sep="", collapse=" ")
}


> sapply(name, .simpleCap)

zip code         state   final count 
"Zip Code"       "State" "Final Count"

回答8:

The package BBmisc now contains the function capitalizeStrings.

library("BBmisc")
capitalizeStrings(c("the taIl", "wags The dOg", "That Looks fuNny!")
    , all.words = TRUE, lower.back = TRUE)
[1] "The Tail"          "Wags The Dog"      "That Looks Funny!"

回答9:

Alternative way with substring and regexpr:

substring(name, 1) <- toupper(substring(name, 1, 1))
pos <- regexpr(" ", name, perl=TRUE) + 1
substring(name, pos) <- toupper(substring(name, pos, pos))

回答10:

You could also use the snakecase package:

install.packages("snakecase")
library(snakecase)

name <- c("zip code", "state", "final count")
to_upper_camel_case(name, sep_out = " ")
#> [1] "Zip Code"    "State"       "Final Count"

https://github.com/Tazinho/snakecase

回答11:

This gives capital Letters to all major words

library(lettercase)
xString = str_title_case(xString)

来源：https://stackoverflow.com/questions/6364783/capitalize-the-first-letter-of-both-words-in-a-two-word-string

标签

string

title-case