| length {base} | R Documentation |
Length of an Object
Description
Get or set the length of vectors (including lists) and factors, and of any other R object for which a method has been defined.
Usage
length(x)
length(x) <- value
Arguments
x |
a vector or list or factor. |
value |
an integer. |
Details
Both functions are generic: you can write methods to handle specific classes of objects, see InternalMethods.
The replacement form can be used to reset the length of a vector. If
a vector is shortened, extra values are discarded and when a vector is
lengthened, it is padded out to its new length with NAs.
Value
The length of x as an integer of length 1,
if x is (or can be coerced to) a vector or list. Otherwise,
length returns NA.
References
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth \& Brooks/Cole.
See Also
nchar for counting the number of characters in
character vectors.
Examples
length(diag(4))# = 16 (4 x 4)
length(options())# 12 or more
length(y ~ x1 + x2 + x3)# 3
length(expression(x, {y <- x^2; y+2}, x^y)) # 3