R: Join multiple strings into a single string.

str_c {stringr} | R Documentation

## Join multiple strings into a single string.

### Description

To understand how `str_c` works, you need to imagine that you are building up a matrix of strings. Each input argument forms a column, and is expanded to the length of the longest argument, using the usual recyling rules. The `sep` string is inserted between each column. If collapse is `NULL` each row is collapsed into a single string. If non-`NULL` that string is inserted at the end of each row, and the entire matrix collapsed to a single string.

### Usage

    str_c(..., sep = "", collapse = NULL)

### Arguments

`...` | One or more character vectors. Zero length arguments are removed. Short arguments are recycled to the length of the longest. Like most other R functions, missing values are "infectious": whenever a missing value is combined with another string the result will always be missing. Use `str_replace_na()` to convert `NA` to `"NA"`
`sep` | String to insert between input vectors.
`collapse` | Optional string used to combine input vectors into single string.

### Value

If `collapse = NULL` (the default) a character vector with length equal to the longest input string. If `collapse` is non-NULL, a character vector of length 1.

### See Also

`paste()` for equivalent base R functionality, and `stringi::stri_join()` which this function wraps

### Examples

    str_c("Letter: ", letters)
    str_c("Letter", letters, sep = ": ")
    str_c(letters, " is for", "...")
    str_c(letters[-26], " comes before ", letters[-1])

    str_c(letters, collapse = "")
    str_c(letters, collapse = ", ")

    # Missing inputs give missing outputs
    str_c(c("a", NA, "b"), "-d")
    # Use str_replace_NA to display literal NAs:
    str_c(str_replace_na(c("a", NA, "b")), "-d")

[Package stringr version 1.3.1 Index]