R: Count the Number of Characters (Bytes)

nchar {base}

R Documentation

Count the Number of Characters (Bytes)

Description

nchar takes a character vector as an argument and returns a vector whose elements contain the sizes of the corresponding elements of x.

Usage

nchar(x, type = "bytes")

Arguments

x

character vector, or a vector to be coerced to a character vector.

type

character string: partial matching to one of c("bytes", "chars", "width"). See Details.

Details

The ‘size’ of a character string can be measured in one of three ways

bytes: The number of bytes needed to store the string (plus in C a final terminator which is not counted).
chars: The number of human-readable characters.
width: The number of columns cat will use to print the string in a monospaced font. The same as chars if this cannot be calculated.

These will often be the same, and almost always will be in single-byte locales. There will be differences between the first two with multibyte character sequences, e.g. in UTF-8 locales. If the byte stream contains embedded nul bytes, type = "bytes" looks at all the bytes whereas the other two types look only at the string as printed by cat, up to the first nul byte.

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.

Value

An integer vector giving the sizes of each element, currently always 2 for missing values (for NA).

If an element is 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")) is a test of validity.

Names, dims and dimnames are copied from the input.

Note

This does not by default give the number of characters that will be used to print() the string. Use encodeString to find the characters used to print the string.

Embedded nul bytes are included in the byte count (but not the final nul).

References

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth \& Brooks/Cole.

Examples

x <- c("asfef","qwerty","yuiop[","b","stuff.blah.yech")
nchar(x)
# 5  6  6  1 15

nchar(deparse(mean))
# 18 17

[Package base version 2.5.0 ]