CODEWITHSUNDEEP
rlistpaste
Alex
Alex

Reputation: 4180

How to paste 2 lists (of equal length) without using a loop to form a new list

Say I have two lists:

  a = list(1,2)
  b = list("x","y")
        #a
        #[[1]]
        #[1] 1

        #[[2]]
        #[1] 2

        #b
        #[[1]]
        #[1] "x"

        #[[2]]
        #[1] "y"

I would like the following result:

        #[[1]]
        #[1] "1x"

        #[[2]]
        #[1] "2y"

I tried the following: 

  lapply(a, paste, b)

But the result was not what I expected: 

        #[[1]]
        #[1] "1 x" "1 y"

        #[[2]]
        #[1] "2 x" "2 y"

I wonder if there is any way to get the desired result - without resorting to any added package or loop.

Thank you in advance!!!

Upvotes: 0

Views: 1197

Answers (2)

Tyler Rinker
Tyler Rinker

Reputation: 109994

jigr's answer is correct but I wanted to address your attempted solution. You were at the 1 yard line, run it in for the touch down. You didn't supply the separator to lapply so paste uses the default " ". Either supply that separator (sep="") or even better use paste0 (available with R version <= 2.15) which defaults to the "" separator.

a = list(1,2)
b = list("x","y")

lapply(a, paste, b, sep="")
lapply(a, paste0, b)

Upvotes: 0

johannes
johannes

Reputation: 14453

Here is one suggestion:

as.list(paste(a,b, sep=""))
[[1]]
[1] "1x"

[[2]]
[1] "2y"

Upvotes: 3

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