问题
How to find the length of a string (number of characters in a string) without splitting it in R? I know how to find the length of a list but not of a string.
And what about Unicode strings? How do I find the length (in bytes) and the number of characters (runes, symbols) in a Unicode string?
Related Question:
- How to find the "real" number of characters in a Unicode string in R
回答1:
See ?nchar. For example:
> nchar("foo")
[1] 3
> set.seed(10)
> strn <- paste(sample(LETTERS, 10), collapse = "")
> strn
[1] "NHKPBEFTLY"
> nchar(strn)
[1] 10
回答2:
Use stringi package and stri_length function
> stri_length(c("ala ma kota","ABC",NA))
[1] 11 3 NA
Why? Because it is the FASTEST among presented solutions :)
require(microbenchmark)
require(stringi)
require(stringr)
x <- c(letters,NA,paste(sample(letters,2000,TRUE),collapse=" "))
microbenchmark(nchar(x),str_length(x),stri_length(x))
Unit: microseconds
expr min lq median uq max neval
nchar(x) 11.868 12.776 13.1590 13.6475 41.815 100
str_length(x) 30.715 33.159 33.6825 34.1360 173.400 100
stri_length(x) 2.653 3.281 4.0495 4.5380 19.966 100
and also works fine with NA's
nchar(NA)
## [1] 2
stri_length(NA)
## [1] NA
回答3:
nchar("STRING")
Check out this
回答4:
You could also use the stringr package:
library(stringr)
str_length("foo")
[1] 3
回答5:
The keepNA = TRUE option prevents problems with NA
nchar(NA)
## [1] 2
nchar(NA, keepNA=TRUE)
## [1] NA
回答6:
nchar(YOURSTRING)
you may need to convert to a character vector first;
nchar(as.character(YOURSTRING))
来源：https://stackoverflow.com/questions/11134812/how-to-find-the-length-of-a-string-in-r