Fill up a list using an existing vector and a double for loop

Question

I would like to have a list where each item is "Born in " each of the cities of the cities vector.

cities <- c("Lausanne", "Zurich", "Geneva")

mylist <- list()

for (i in 1:length(cities)){
  for (city in cities){
    born <- paste0("Born in ", city)
    mylist[[i]] <- born
  }
}

I need it in the list format because I have much more complex data and would actually be adding dataframes into the list. I would like to understand how the double loop would work (one for items and one for length).

Thank you!

I need to put it in a list because I have more complex data and I would like to understand how the loop would work — InesGuardans, Dec 03 '19 at 10:09
`for (i in 1:length(cities)){mylist[[i]] <- paste0("Born in ", cities[i])}` — GKi, Dec 03 '19 at 10:11
I guess you just need one `for` loop, otherwise you would create a list of duplicates — ThomasIsCoding, Dec 03 '19 at 10:20

score 2 · Answer 1 · answered Dec 03 '19 at 10:13

If you want to put the data in list you can use as.list

as.list(paste0("Born in ", cities))

#[[1]]
#[1] "Born in Lausanne"

#[[2]]
#[1] "Born in Zurich"

#[[3]]
#[1] "Born in Geneva"

If you really want to use for loop, you'll need only one loop

mylist <- vector("list", length(cities))
for (i in seq_along(cities)) {
    mylist[[i]] <- paste0("Born in ", cities[i])
}

Fill up a list using an existing vector and a double for loop

1 Answers1