Concatenate Strings

Description

Concatenate vectors after converting to character.

Usage

paste (..., sep = " ", collapse = NULL)
paste0(..., collapse = NULL)

Arguments

Details

paste converts its arguments (via as.character) to character strings, and concatenates them (separating them by the string given by sep). If the arguments are vectors, they are concatenated term-by-term to give a character vector result. Vector arguments are recycled as needed, with zero-length arguments being recycled to "".

Note that paste() coerces NA_character_, the character missing value, to "NA" which may seem undesirable, e.g., when pasting two character vectors, or very desirable, e.g. in paste("the value of p is ", p).

paste0(..., collapse) is equivalent to paste(..., sep = "", collapse), slightly more efficiently.

If a value is specified for collapse, the values in the result are then concatenated into a single string, with the elements being separated by the value of collapse.

Value

A character vector of the concatenated values. This will be of length zero if all the objects are, unless collapse is non-NULL in which case it is a single empty string.

If any input into an element of the result is in UTF-8 (and none are declared with encoding "bytes", (see Encoding), that element will be in UTF-8, otherwise in the current encoding in which case the encoding of the element is declared if the current locale is either Latin-1 or UTF-8, at least one of the corresponding inputs (including separators) had a declared encoding and all inputs were either ASCII or declared.

If an input into an element is declared with encoding "bytes", no translation will be done of any of the elements and the resulting element will have encoding "bytes". If collapse is non-NULL, this applies also to the second, collapsing, phase, but some translation may have been done in pasting object together in the first phase.

References

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.

See Also

toString typically calls paste(*, collapse=", "). String manipulation with as.character, substr, nchar, strsplit; further, cat which concatenates and writes to a file, and sprintf for C like string construction.

‘plotmath’ for the use of paste in plot annotation.

Examples

## When passing a single vector, paste0 and paste work like as.character.
paste0(1:12)
paste(1:12)        # same
as.character(1:12) # same

## If you pass several vectors to paste0, they are concatenated in a
## vectorized way.
(nth <- paste0(1:12, c("st", "nd", "rd", rep("th", 9))))

## paste works the same, but separates each input with a space.
## Notice that the recycling rules make every input as long as the longest input.
paste(month.abb, "is the", nth, "month of the year.")
paste(month.abb, letters)

## You can change the separator by passing a sep argument
## which can be multiple characters.
paste(month.abb, "is the", nth, "month of the year.", sep = "_*_")

## To collapse the output into a single string, pass a collapse argument.
paste0(nth, collapse = ", ")

## For inputs of length 1, use the sep argument rather than collapse
paste("1st", "2nd", "3rd", collapse = ", ") # probably not what you wanted
paste("1st", "2nd", "3rd", sep = ", ")

## You can combine the sep and collapse arguments together.
paste(month.abb, nth, sep = ": ", collapse = "; ")

## Using paste() in combination with strwrap() can be useful
## for dealing with long strings.
(title <- paste(strwrap(
    "Stopping distance of cars (ft) vs. speed (mph) from Ezekiel (1930)",
    width = 30), collapse = "\n"))
plot(dist ~ speed, cars, main = title)

Results

R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> library(base)
> png(filename="/home/ddbj/snapshot/RGM3/R_rel/result/base/paste.Rd_%03d_medium.png", width=480, height=480)
> ### Name: paste
> ### Title: Concatenate Strings
> ### Aliases: paste paste0
> ### Keywords: character
> 
> ### ** Examples
> 
> ## When passing a single vector, paste0 and paste work like as.character.
> paste0(1:12)
 [1] "1"  "2"  "3"  "4"  "5"  "6"  "7"  "8"  "9"  "10" "11" "12"
> paste(1:12)        # same
 [1] "1"  "2"  "3"  "4"  "5"  "6"  "7"  "8"  "9"  "10" "11" "12"
> as.character(1:12) # same
 [1] "1"  "2"  "3"  "4"  "5"  "6"  "7"  "8"  "9"  "10" "11" "12"
> 
> ## If you pass several vectors to paste0, they are concatenated in a
> ## vectorized way.
> (nth <- paste0(1:12, c("st", "nd", "rd", rep("th", 9))))
 [1] "1st"  "2nd"  "3rd"  "4th"  "5th"  "6th"  "7th"  "8th"  "9th"  "10th"
[11] "11th" "12th"
> 
> ## paste works the same, but separates each input with a space.
> ## Notice that the recycling rules make every input as long as the longest input.
> paste(month.abb, "is the", nth, "month of the year.")
 [1] "Jan is the 1st month of the year."  "Feb is the 2nd month of the year." 
 [3] "Mar is the 3rd month of the year."  "Apr is the 4th month of the year." 
 [5] "May is the 5th month of the year."  "Jun is the 6th month of the year." 
 [7] "Jul is the 7th month of the year."  "Aug is the 8th month of the year." 
 [9] "Sep is the 9th month of the year."  "Oct is the 10th month of the year."
[11] "Nov is the 11th month of the year." "Dec is the 12th month of the year."
> paste(month.abb, letters)
 [1] "Jan a" "Feb b" "Mar c" "Apr d" "May e" "Jun f" "Jul g" "Aug h" "Sep i"
[10] "Oct j" "Nov k" "Dec l" "Jan m" "Feb n" "Mar o" "Apr p" "May q" "Jun r"
[19] "Jul s" "Aug t" "Sep u" "Oct v" "Nov w" "Dec x" "Jan y" "Feb z"
> 
> ## You can change the separator by passing a sep argument
> ## which can be multiple characters.
> paste(month.abb, "is the", nth, "month of the year.", sep = "_*_")
 [1] "Jan_*_is the_*_1st_*_month of the year." 
 [2] "Feb_*_is the_*_2nd_*_month of the year." 
 [3] "Mar_*_is the_*_3rd_*_month of the year." 
 [4] "Apr_*_is the_*_4th_*_month of the year." 
 [5] "May_*_is the_*_5th_*_month of the year." 
 [6] "Jun_*_is the_*_6th_*_month of the year." 
 [7] "Jul_*_is the_*_7th_*_month of the year." 
 [8] "Aug_*_is the_*_8th_*_month of the year." 
 [9] "Sep_*_is the_*_9th_*_month of the year." 
[10] "Oct_*_is the_*_10th_*_month of the year."
[11] "Nov_*_is the_*_11th_*_month of the year."
[12] "Dec_*_is the_*_12th_*_month of the year."
> 
> ## To collapse the output into a single string, pass a collapse argument.
> paste0(nth, collapse = ", ")
[1] "1st, 2nd, 3rd, 4th, 5th, 6th, 7th, 8th, 9th, 10th, 11th, 12th"
> 
> ## For inputs of length 1, use the sep argument rather than collapse
> paste("1st", "2nd", "3rd", collapse = ", ") # probably not what you wanted
[1] "1st 2nd 3rd"
> paste("1st", "2nd", "3rd", sep = ", ")
[1] "1st, 2nd, 3rd"
> 
> ## You can combine the sep and collapse arguments together.
> paste(month.abb, nth, sep = ": ", collapse = "; ")
[1] "Jan: 1st; Feb: 2nd; Mar: 3rd; Apr: 4th; May: 5th; Jun: 6th; Jul: 7th; Aug: 8th; Sep: 9th; Oct: 10th; Nov: 11th; Dec: 12th"
> 
> ## Using paste() in combination with strwrap() can be useful
> ## for dealing with long strings.
> (title <- paste(strwrap(
+     "Stopping distance of cars (ft) vs. speed (mph) from Ezekiel (1930)",
+     width = 30), collapse = "\n"))
[1] "Stopping distance of cars\n(ft) vs. speed (mph) from\nEzekiel (1930)"
> plot(dist ~ speed, cars, main = title)
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>