Check that x is character

Check that x is a character vector of the correct length with only allowed values.

Usage

all_characters(
  x,
  allow_empty = FALSE,
  allow_zerolength = FALSE,
  allow_NA = FALSE
)

is_character(
  x,
  allow_empty = FALSE,
  allow_zerolength = FALSE,
  allow_NA = FALSE
)

Arguments

x

object to check.

allow_empty

TRUE or FALSE: allow empty strings ("") in x?

allow_zerolength

TRUE or FALSE: allow zero-length x of the correct type?

allow_NA

TRUE or FALSE: allow NA of the correct type in x?

Value

TRUE or FALSE indicating if x is a character vector of the correct length with only allowed values.

Details

is_character() and all_characters() return TRUE for empty strings ("") if allow_empty is TRUE, and for NA_character_ if allow_NA is TRUE.

is_character() returns TRUE for x with length one and all_characters() returns TRUE for x with length larger than zero. Both functions return TRUE for character-type zero-length x if allow_zerolength is TRUE.

See also

Other collections of checks on type and length: all_names(), is_logical(), is_natural(), is_number(), is_path(), is_zerolength()

Examples

is_character("a") # TRUE
#> [1] TRUE
is_character(c("a", "b")) # FALSE: incorrect length
#> [1] FALSE
all_characters(c("a", "b")) # TRUE
#> [1] TRUE
is_character(1) # FALSE: incorrect type
#> [1] FALSE
is_character(NA_character_) # FALSE: default 'allow_NA' is FALSE
#> [1] FALSE
is_character(NA_character_, allow_NA = TRUE) # TRUE
#> [1] TRUE
is_character(NA, allow_NA = TRUE) # FALSE: incorrect type
#> [1] FALSE