How to for-Loop Over List Elements in R (Example Code)
In this article, I’ll illustrate how to loop over list elements in the R programming language.
Example Data
list_object <- list(1:7, # Exemplifying list in R "hahahaha", letters[10:5], "lala", "lolo") list_object # Returning list to console # [[1]] # [1] 1 2 3 4 5 6 7 # # [[2]] # [1] "hahahaha" # # [[3]] # [1] "j" "i" "h" "g" "f" "e" # # [[4]] # [1] "lala" # # [[5]] # [1] "lolo" |
list_object <- list(1:7, # Exemplifying list in R "hahahaha", letters[10:5], "lala", "lolo") list_object # Returning list to console # [[1]] # [1] 1 2 3 4 5 6 7 # # [[2]] # [1] "hahahaha" # # [[3]] # [1] "j" "i" "h" "g" "f" "e" # # [[4]] # [1] "lala" # # [[5]] # [1] "lolo"
Example: Looping Through List Elements Using for-Loop
for(i in 1:length(list_object)) { # Starting the for-loop list_object[[i]] <- rep(list_object[[i]], 3) # Modifying list } |
for(i in 1:length(list_object)) { # Starting the for-loop list_object[[i]] <- rep(list_object[[i]], 3) # Modifying list }
list_object # Returning new list to console # [[1]] # [1] 1 2 3 4 5 6 7 1 2 3 4 5 6 7 1 2 3 4 5 6 7 # # [[2]] # [1] "hahahaha" "hahahaha" "hahahaha" # # [[3]] # [1] "j" "i" "h" "g" "f" "e" "j" "i" "h" "g" "f" "e" "j" "i" "h" "g" "f" "e" # # [[4]] # [1] "lala" "lala" "lala" # # [[5]] # [1] "lolo" "lolo" "lolo" |
list_object # Returning new list to console # [[1]] # [1] 1 2 3 4 5 6 7 1 2 3 4 5 6 7 1 2 3 4 5 6 7 # # [[2]] # [1] "hahahaha" "hahahaha" "hahahaha" # # [[3]] # [1] "j" "i" "h" "g" "f" "e" "j" "i" "h" "g" "f" "e" "j" "i" "h" "g" "f" "e" # # [[4]] # [1] "lala" "lala" "lala" # # [[5]] # [1] "lolo" "lolo" "lolo"