[r] How to remove all whitespace from a string?

So " xx yy 11 22 33 " will become "xxyy112233". How can I achieve this?

Use [[:blank:]] to match any kind of horizontal white_space characters.

gsub("[[:blank:]]", "", " xx yy 11 22  33 ")
# [1] "xxyy112233"

This way you can remove all spaces from all character variables in your data frame. If you would prefer to choose only some of the variables, use mutateor mutate_at.

library(dplyr)
library(stringr)

remove_all_ws<- function(string){
    return(gsub(" ", "", str_squish(string)))
}

df<-df %>%  mutate_if(is.character, remove_all_ws)

Another approach can be taken into account

library(stringr)
str_replace_all(" xx yy 11 22  33 ", regex("\\s*"), "")

#[1] "xxyy112233"

\\s: Matches Space, tab, vertical tab, newline, form feed, carriage return

*: Matches at least 0 times

x = "xx yy 11 22 33"

gsub(" ", "", x)

> [1] "xxyy112233"

The function str_squish() from package stringr of tidyverse does the magic!

library(dplyr)
library(stringr)

df <- data.frame(a = c("  aZe  aze s", "wxc  s     aze   "), 
                 b = c("  12    12 ", "34e e4  "), 
                 stringsAsFactors = FALSE)
df <- df %>%
  rowwise() %>%
  mutate_all(funs(str_squish(.))) %>%
  ungroup()
df

# A tibble: 2 x 2
  a         b     
  <chr>     <chr> 
1 aZe aze s 12 12 
2 wxc s aze 34e e4

I just learned about the "stringr" package to remove white space from the beginning and end of a string with str_trim( , side="both") but it also has a replacement function so that:

a <- " xx yy 11 22 33 " 
str_replace_all(string=a, pattern=" ", repl="")

[1] "xxyy112233"

Please note that soultions written above removes only space. If you want also to remove tab or new line use stri_replace_all_charclass from stringi package.

library(stringi)
stri_replace_all_charclass("   ala \t  ma \n kota  ", "\\p{WHITE_SPACE}", "")
## [1] "alamakota"

From stringr library you could try this:

1. Remove consecutive fill blanks

2. Remove fill blank

   library(stringr)

               2.         1.
               |          |
               V          V
   
       str_replace_all(str_trim(" xx yy 11 22  33 "), " ", "")