R: Trim Characters from the Left and/or Right Side of a String

stri_trim_both {stringi} | R Documentation

## Trim Characters from the Left and/or Right Side of a String

### Description

These functions may be used e.g. to get rid of unnecessary whitespaces from strings. Trimming ends at the first or starts at the last `pattern` match.

### Usage

    stri_trim_both(str, pattern = "\\P{Wspace}")

    stri_trim_left(str, pattern = "\\P{Wspace}")

    stri_trim_right(str, pattern = "\\P{Wspace}")

    stri_trim(str, side = c("both", "left", "right"), pattern = "\\P{Wspace}")

### Arguments

`str` | a character vector of strings to be trimmed
`pattern` | a single pattern, specifying character classes that should be preserved (see stringi-search-charclass). Defaults to '`\P{Wspace}`.
`side` | character [`stri_trim` only]; defaults to `"both"`

### Details

Vectorized over `str` and `pattern`.

`stri_trim` is a wrapper, which calls `stri_trim_left` or `stri_trim_right` as appropriate. It's slightly slower than trim_left or trim_right, and so shouldn't be used except for convenience.

Contrary to many other string processing libraries, our trimming functions are quite general. A character class, given by `pattern`, may be adjusted to suit your needs (most often you will use the default value). On the other hand, for replacing pattern matches with arbitrary replacement string, see `stri_replace`.

Interestingly, with these functions you may sometimes extract data, which in some cases require using regular expressions. E.g. you may get `"23.5"` out of `"total of 23.5 bitcoins"`.

For trimming whitespaces, please note the difference between Unicode binary property '`\p{Wspace}`' (more general) and general character category '`\p{Z}`', see stringi-search-charclass.

### Value

All these functions return a character vector.

### See Also

Other search_replace: `stri_replace_all`, `stri_replace_na`, `stringi-search`

Other search_charclass: `stringi-search-charclass`, `stringi-search`

### Examples

    stri_trim_left("               aaa")
    stri_trim_right("rexamine.com/", "\\p{P}")
    stri_trim_both(" Total of 23.5 bitcoins. ", "\\p{N}")
    stri_trim_both(" Total of 23.5 bitcoins. ", "\\p{L}")

[Package stringi version 1.2.4 Index]