r用0和破折号格式化数字

尝试 formatC :

formatC(x, width = 7, format = "d", flag = "0", big.mark = '-')
# [1] "0-012-344" "0-233-345" "7-233-433" "9-343-883" "3-432-837"

使用的数据:

x <- scan(textConnection('12344
233345
7233433
9343883
3432837'))

my_format <- function(num){
x <- sprintf("%07d", num)
paste0(substr(x, 1,1), "-",
    substr(x, 2,4), "-",
    substr(x, 5,7))
}

nums <-  c(12344,233345,7233433,9343883,3432837)
my_format(nums)

# gives
[1] "0-012-344" "0-233-345" "7-233-433" "9-343-883" "3-432-837"

我们可以使用 stringr 和 purrr

# Data
numbers <- c("12344", "233345", "7233433", "9343883", "3432837")

# Load package
library(stringr)
library(purrr)

# A function to add dash line
trans_num <- function(number){
  part1 <- str_sub(number, start = 1, end = 1)
  part2 <- str_sub(number, start = 2, end = 4)
  part3 <- str_sub(number, start = 5)
  return(paste(part1, part2, part3, sep = "-"))
}

numbers %>%
  str_pad(width = 7, pad = "0") %>%
  map_chr(trans_num)
[1] "0-012-344" "0-233-345" "7-233-433" "9-343-883" "3-432-837"

这是一个 base R 带有的选项 sub sprintf

sub("(.)(.{3})", '\\1-\\2-', sprintf("%07d", x))
#[1] "0-012-344" "0-233-345" "7-233-433" "9-343-883" "3-432-837"

首先,您需要构建长度为7、前导为零的字符串。我用过 this :

strReverse <- function(x)
    sapply(lapply(strsplit(x, NULL), rev), paste, collapse="")

v = as.character(read.table(text = "   12344
  233345
 7233433
 9343883
 3432837", header = FALSE)[,1])

v1 = strReverse( substring(paste0(strReverse(v), "0000"), 1, 7))

> v1
[1] "0012344" "0233345" "7233433" "9343883" "3432837"

现在,添加破折号应该很简单:

paste0(substring(v1,1,1), "-", substring(v1,2,4), "-", substring(v1,5,7))