How to get all words which starts with capital letter?

Given:

text <- "fsfs blabla Honda t Asus"

text <- "fsfs blabla Honda t Asus"

I want to get result:

[1] "Honda" "Asus"

[1] "Honda" "Asus"

I have done it by this function:

foo <- function(txt){
txtNew <- txt
txtNew2 <- txt
txtMemory <- ""
while(txtNew != txtMemory){
txtNew <- txtNew2
txtMemory <- txtNew2
txtNew <- gsub("\s[a-z]","",txtNew)
txtNew2 <- paste0(" ", txtNew)
}
txtNew <- sub("^\s+", "", txtNew)
strsplit(txtNew, " ")
}
foo("fsfs blabla Honda t Asus")


but I guess there is much easier way in R?

4 Answers
4

We can use str_extract to match a capital letter ([A-Z]) followed by a word boundary (\b) followed by one or more word characters

str_extract

[A-Z]

\b

library(stringr)
str_extract_all(text, "\b[A-Z]\w+")[[1]]
#[1] "Honda" "Asus"


Or with gregexpr/regmatches from base R

gregexpr/regmatches

base R

regmatches(text, gregexpr("\b[A-Z]\w+", text))
#[1] "Honda" "Asus"


In base R, you could do

grep("^[A-Z]", scan(textConnection("fsfs blabla Honda t Asus"), ""), value=TRUE)
Read 5 items
[1] "Honda" "Asus"


Here, scan reads in the text and splits it by white space. Then grep with values=TRUE returns all elements in the character vector which match the subexpression "^[A-Z]" which can be read "starts with a capital letter."

scan

grep

In place of scan, you could use strsplit / unlist for the same result.

scan

strsplit

grep("^[A-Z]", unlist(strsplit("fsfs blabla Honda t Asus", " ")), value=TRUE)


Here's a solution without regular expressions:

text <- "fsfs blabla Honda t Asus"
x <- strsplit(text, " ", T)[[1]]
x[substr(x, 1, 1) %in% LETTERS]
# [1] "Honda" "Asus"


I would do so:

const str = "fsfs blabla Honda t Asus";
const regex = /([A-Z]w+)/g;
const result = ;
let m;
while ((m = regex.exec(str)) !== null) result.push(m[1]);
$('#result').html(JSON.stringify(result));

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<p id="result"></p>

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