Extract the substring from the string as well as the rest of the string

Question

I want to store the first character of a string in a variable and the rest of the string in another variable. For instance:

x <- "foo"
prefix <- substr(x, 1, 1)
suffix <- substring(x, 2)

However, it seems wasteful to call substrand substring. Is there no way to extract both the substring and the rest of the string (the "difference" between the substring and the source string)?

Answer 1

Maybe something like this:

substring(x, c(1, 2), c(1, nchar(x)))
# [1] "f"  "oo"

Answer 2

Here is an idea using regex,

strsplit(gsub('^([A-z]{1})([A-z]+)$', '\\1_\\2', x), '_')
#[[1]]
#[1] "f"  "oo"

Answer 3

str_split stringr:

require(stringr)
x<-c("foo", "hello", "world")
str_split(x,"(?<=.{1})",2)
#[[1]]
#[1] "f"  "oo"
#[[2]]
#[1] "h"    "ello"
#[[3]]
#[1] "w"    "orld"

Answer 4

separate tidyr

library(tidyr)
separate(data_frame(x), x, into = c('prefix', 'suffix'), sep=1)
# A tibble: 3 × 2
#  prefix suffix 
#* <chr> <chr>
#1     f    oo
#2     h  ello
#3     w  orld

x<-c("foo", "hello", "world")