在向量的每个其他元素上粘贴一个字符串

Question

我有这样的矢量:

test <- c("a","b","c","d")
test
[1] "a" "b" "c" "d"

我想将一个字符串,例如"_2"粘贴到矢量的每个其他元素上,以获得:

"a" "b_2" "c" "d_2"

我试过这个命令:

ifelse(test %in% seq(1, length(test), 2), test, paste(test, "_2", sep=""))

但这只是给了我:

"a_2" "b_2" "c_2" "d_2"

这是错的.有关如何正确执行此操作的任何建议？谢谢!

Answer 1

怎么样

paste0(c("a","b","c","d"), c("", "_2"))

[1] "a"   "b_2" "c"   "d_2"