Working with Strings

Tools for working with character/text strings without importing the stringr package.

Usage

pad(x, width, side = c("right", "left", "both"))

squish(x)

trim(x, side = c("both", "left", "right"), whitespace = "[ \t\r\n]")

capture(text, pattern)

Arguments

x: A character vector.
width: integer(1). The minimum width of padding for each element.
side: character(1). Pad to the left or right.
whitespace: A string specifying a regular expression to match (one character of) "white space".
text: A character vector where matches are sought.
pattern: character(1). A string containing a group capture regex.

Functions

pad(): Similar to stringr::str_pad() but does uses only a blank space as the padding character.
squish(): The inverse of pad(), removes whitespace on both sides and replicated internal whitespace. Similar to stringr::str_squish().
trim(): A wrapper around trimws() but with unified argument names.
capture(): Uses "group capture" regular expression from the pattern argument to extract matches from character string(s). Analogous to stringr::str_extract().

base vs stringr

Below is a convenient table of the stringr to base R equivalents:

stringr	base R
`stringr::str_c()`	`paste()`
`stringr::str_count()`	`gregexpr()` + `attr(x, "match.length")`]
`stringr::str_dup()`	`strrep()`
`stringr::str_detect()`	`grepl()`
`stringr::str_flatten()`	`paste(..., collapse = "")`
`stringr::str_glue()`	`sprintf()`
`stringr::str_length()`	`nchar()`
`stringr::str_locate_all()`	`regexpr()`
`stringr::str_match()`	`match()`
`stringr::str_order()`	`order()`
`stringr::str_remove()`	`sub(..., replacement = "")`
`stringr::str_remove_all()`	`gsub(..., replacement = "")`
`stringr::str_replace()`	`sub()`
`stringr::str_replace_all()`	`gsub()`
`stringr::str_sort()`	`sort()`
`stringr::str_split()`	`strsplit()`
`stringr::str_sub()`	`substr()`, `substring()`, `strtrim()`
`stringr::str_subset()`	`grep(..., value = TRUE)`
`stringr::str_to_lower()`	`tolower()`
`stringr::str_to_upper()`	`toupper()`
`stringr::str_trim()`	`trimws()`
`stringr::str_which()`	`grep()`
`stringr::str_wrap()`	`strwrap()`

And those found only in helpr:

stringr	helpr
`stringr::str_extract()`	`capture()`, `gsub(..., replacement = "\\1")`
`stringr::str_squish()`	`squish()`
`stringr::str_pad()`	`pad()` or `sprintf()`
`stringr::str_trim()`	`trim()`

Examples

pad("tidyverse", 20)
#> [1] "tidyverse           "
pad("tidyverse", 20, "left")
#> [1] "           tidyverse"
pad("tidyverse", 20, "both")
#> [1] "     tidyverse      "

squish("  abcd   efgh   ")
#> [1] "abcd efgh"
squish("  abcd   efgh   .")
#> [1] "abcd efgh ."

trim("  abcd   efgh   ")
#> [1] "abcd   efgh"
trim("  abcd   efgh   .")
#> [1] "abcd   efgh   ."

# extract the group 'oo'
capture(c("foo", "bar", "boo", "oops"), "(oo)")
#>      1
#> 1   oo
#> 2 <NA>
#> 3   oo
#> 4   oo

# capture multiple groups
capture(c("foo", "bar", "boo", "oops-e-doo"), "(.*)(oo)")
#>          1    2
#> 1        f   oo
#> 2     <NA> <NA>
#> 3        b   oo
#> 4 oops-e-d   oo

Usage

Arguments

Functions

base vs stringr

See also

Examples