Combining list string elements with R

Question

I have a list containing multiple strings in each list position (see below). As you can see, in each position of the list is two string values. I want to combine both strings so that they form one string and insert a + symbol in between them.

print(my_list)

>> [[1]]
>> [1] "A" "B"    

>> [[2]]
>> [1] "C" "D" "E" "F"

>> [[3]]
>> [1] "G" "H"   
...

This would be my desired output..

print(my_list)

>> [[1]]
>> [1] "A + B"    

>> [[2]]
>> [1] "C + D + E + F"

>> [[3]]
>> [1] "G + H"   
...

So far (as a starting point) I have tried using "paste" in a for loop, like this..

for (i in my_list){
  print(paste(i, sep = "+"))
}

This did not have the intended effect. It simply duplicated each list item and did not insert a + anywhere. Here is the output..

print(my_list)

>> [1] "A" "B" 
>> [1] "A" "B"    

>> [2] "C" "D" "E" "F"
>> [2] "C" "D" "E" "F"

>> [3] "G" "H"  
>> [3] "G" "H"   
...

Any ideas? Cheers

Does this answer your question? How do you paste list of items in R — user438383
– user438383, Commented Aug 12, 2022 at 23:29

dcsuka · Accepted Answer · 2022-08-12 23:28:22Z

1

A simple lapply and paste does the trick:

lapply(mylist, function(x) paste(x, collapse = " + "))

# [[1]]
# [1] "A + B"
# 
# [[2]]
# [1] "C + D + E + F"
# 
# [[3]]
# [1] "G + H"

Sample Data:

mylist <- list(c("A", "B"),
     c("C", "D", "E", "F"),
     c("G", "H"))

answered Aug 12, 2022 at 23:28

dcsuka

3,0073 gold badges8 silver badges28 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Combining list string elements with R

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related