Remove Patterns from Strings

str_remove_first() removes the first occurrence of a pattern in each string. str_remove_all() removes all occurrences of a pattern in each string.

Usage

str_remove_first(strings, pattern, fixed = FALSE)

str_remove_all(strings, pattern, fixed = FALSE)

str_remove_nth(strings, pattern, n, fixed = FALSE)

str_remove_last(strings, pattern, fixed = FALSE)

Arguments

strings

A character vector, where each element of the vector is a character string.

pattern

A single character string to be searched for in each element of strings. By default, pattern is interpreted as a regular expression (regex). If the fixed argument is set to TRUE, pattern will be treated as a literal string to be matched exactly.

fixed

Logical; whether pattern should be matched exactly, treating regex special characters as regular string characters. Default FALSE.

n

(str_remove_nth only) Integer, the nth occurrence of the pattern to replace. Negative values count back from the end.

Value

A character vector of the same length as strings, with the specified pattern removed. For str_remove_first(), only the first occurrence of the pattern in each string is removed. For str_remove_all(), all occurrences of the pattern in each string are removed.

Details

These functions are built using the base R regular expression functions. {suitestrings} uses Perl-compatible Regular Expressions (PCRE). This is achieved by setting perl = TRUE in the underlying base functions. See R's regexp documentation for info on the regex implementation. For complete syntax details see https://www.pcre.org/current/doc/html/

See also

str_replace_all() and family for replacing patterns with specific text. str_remove functions are equivalent to calling those with replacement = ""

Examples

string <- "carrot, car park, cable car"

str_remove_first(string, "car")
#> [1] "rot, car park, cable car"
str_remove_nth(string, "car", 2)
#> [1] "carrot,  park, cable car"
str_remove_last(string, "car")
#> [1] "carrot, car park, cable "
str_remove_all(string, "car")
#> [1] "rot,  park, cable "