Collapse a character vector into a single string

Concatenates all elements in a character vector. Essentially a column-wise variant of dplyr::str_c(). Can accept multiple character vectors, which are returned as separate character strings if join = NULL (the default), or concatenated with a separator supplied to join.

Usage

str_collapse(..., sep = "", join = NULL)

Arguments

...: one or more character vectors
sep: string to insert between elements of each input vector
join: optional string to combine output into a single string. join multiple collapsed vectors. If NULL (default), returns a character vector with each input vector collapsed separately.

Value

If join is NULL, returns a character vector with length equal to the number of vectors passed to .... If join is provided, returns a character vector of length 1.

Details

When only a single character vector is passed to ..., behavior will be similar to stringr::str_c() using the collapse argument. But behavior differs when multiple vectors are passed to ... – see examples. The difference arise because str_collapse() first collapses each vector, then optionally joins the resulting vectors, whereas stringr::str_c() first joins across vectors before collapsing the resulting vector.

Examples

# with just a single character vector, behavior is similar to `stringr::str_c()`
# with the `collapse` argument
abc <- c("a", "b", "c")
str_collapse(abc, sep = "-")
#> [1] "a-b-c"
stringr::str_c(abc, collapse = "-")
#> [1] "a-b-c"

# but behavior differs when multiple vectors are passed
def <- c("d", "e", "f")
str_collapse(abc, def, sep = "-")
#> [1] "a-b-c" "d-e-f"
stringr::str_c(abc, def, collapse = "-")
#> [1] "ad-be-cf"

str_collapse(abc, def, sep = "-", join = " | ")
#> [1] "a-b-c | d-e-f"
stringr::str_c(abc, def, collapse = "-", sep = " | ")
#> [1] "a | d-b | e-c | f"
stringr::str_c(abc, def, sep = "-", collapse = " | ")
#> [1] "a-d | b-e | c-f"

# can accept vectors of different lengths
lmnop <- c("l", "m", "n", "o", "p")
str_collapse(abc, def, lmnop, join = ", ")
#> [1] "abc, def, lmnop"