string - 将字符向量拆分为单个字符？ (与粘贴或 stringr::str_c 相反)

Question

R 中的一个非常基本的问题，但解决方案尚不清楚。

如何将字符向量拆分为各个字符，即与 paste(..., sep='') 或 stringr::str_c() 相反> ?

任何比这更不笨重的东西:

sapply(1:26, function(i) { substr("ABCDEFGHIJKLMNOPQRSTUVWXYZ",i,i) } )
"A" "B" "C" "D" "E" "F" "G" "H" "I" "J" "K" "L" "M" "N" "O" "P" "Q" "R" "S" "T" "U" "V" "W" "X" "Y" "Z"

可以用其他方式完成吗，例如与 strsplit()、stringr::* 或其他什么？

Answer 1

是的，strsplit 可以做到。 strsplit 返回一个列表，因此您可以使用 unlist 将字符串强制为单个字符向量，或使用列表索引 [[1]] 访问第一个元素。

x <- paste(LETTERS, collapse = "")

unlist(strsplit(x, split = ""))
# [1] "A" "B" "C" "D" "E" "F" "G" "H" "I" "J" "K" "L" "M" "N" "O" "P" "Q" "R" "S"
#[20] "T" "U" "V" "W" "X" "Y" "Z"

OR(注意实际上没有必要命名 split 参数)

strsplit(x, "")[[1]]
# [1] "A" "B" "C" "D" "E" "F" "G" "H" "I" "J" "K" "L" "M" "N" "O" "P" "Q" "R" "S"
#[20] "T" "U" "V" "W" "X" "Y" "Z"

您还可以按 NULL 或 character(0) 进行拆分以获得相同的结果。