Extract or replace substrings in a character vector.
substr(x, start, stop) substring(text, first, last = 1000000L) substr(x, start, stop) <- value substring(text, first, last = 1000000L) <- value
- x, text
- a character vector.
- start, first
- integer. The first element to be replaced.
- stop, last
- integer. The last element to be replaced.
- a character vector, recycled if necessary.
When extracting, if
start is larger than the string length then
"" is returned.
For the replacement functions, if
start is larger than the string length then no replacement is done. If the portion to be replaced is longer than the replacement string, then only the portion the length of the string is replaced.
If any argument is an
NA element, the corresponding element of the answer is
Elements of the result will be have the encoding declared as that of the current locale (see
Encoding if the corresponding input had a declared Latin-1 or UTF-8 encoding and the current locale is either Latin-1 or UTF-8.
If an input element has declared
"bytes" encoding, the subsetting is done in units of bytes not characters.
substr, a character vector of the same length and with the same attributes as
x (after possible coercion).
substring, a character vector of length the longest of the arguments. This will have names taken from
x (if it has any after coercion, repeated as needed), and other attributes copied from
x if it is the longest of the arguments).
x with a declared encoding (see
Encoding) will be returned with the same encoding.
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole. (
The S4 version of
last; this version does not.
These functions are often used with
nchar to truncate a display. That does not really work (you want to limit the width, not the number of characters, so it would be better to use
strtrim), but at least make sure you use the default
nchar(type = "c").
Documentation reproduced from R 3.0.1. License: GPL-2.