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nchar takes a character vector as an argument and
returns a vector whose elements contain the sizes of
the corresponding elements of x. nzchar is a fast way to find out if elements of a character
vector are non-empty strings.nchar(x, type = "chars", allowNA = FALSE, keepNA = NA)nzchar(x, keepNA = FALSE)
c("bytes", "chars", "width"). See ‘Details’.NA be returned for invalid
multibyte strings or "bytes"-encoded strings (rather than
throwing an error)?NA be returned where ever
x is NA? If false, nchar() returns
2, as that is the number of printing characters used when
strings are written to output, and nzchar() is TRUE. The
default for nchar(), NA, means to use keepNA = TRUE
unless type is "width". Used to be (implicitly) hard
coded to FALSE in R versions nchar, an integer vector giving the sizes of each element.
For missing values (i.e., NA, i.e., NA_character_),
nchar() returns NA_integer_ if keepNA is
true, and 2, the number of printing characters, if false. type = "width" gives (an approximation to) the number of
columns used in printing each element in a terminal font, taking into
account double-width, zero-width and ‘composing’ characters. If allowNA = TRUE and an element is detected as invalid in a
multi-byte character set such as UTF-8, its number of characters and
the width will be NA. Otherwise the number of characters will
be non-negative, so !is.na(nchar(x, "chars", TRUE)) is a test
of validity. A character string marked with "bytes" encoding (see
Encoding) has a number of bytes, but neither a known
number of characters nor a width, so the latter two types are
NA if allowNA = TRUE, otherwise an error. Names, dims and dimnames are copied from the input. For nzchar, a logical vector of the same length as x,
true if and only if the element has non-zero length; if the element is
NA, nzchar() is true when keepNA is false, as by
default, and NA otherwise.type argument):
bytescharswidthcat will use to
print the string in a monospaced font. The same as chars
if this cannot be calculated.type determines the default for
keepNA). There will be differences between the first two with
multibyte character sequences, e.g. in UTF-8 locales. The internal equivalent of the default method of
as.character is performed on x (so there is no
method dispatch). If you want to operate on non-vector objects
passing them through deparse first will be required.strwidth giving width of strings for plotting;
paste, substr, strsplitx <- c("asfef", "qwerty", "yuiop[", "b", "stuff.blah.yech")
nchar(x)
# 5 6 6 1 15
nchar(deparse(mean))
# 18 17 <-- unless mean differs from base::mean
x[3] <- NA; x
nchar(x, keepNA= TRUE) # 5 6 NA 1 15
nchar(x, keepNA=FALSE) # 5 6 2 1 15
stopifnot(identical(nchar(x ), nchar(x, keepNA= TRUE)),
identical(nchar(x, "w"), nchar(x, keepNA=FALSE)),
identical(is.na(x), is.na(nchar(x))))
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