Select column with the longest string in R

Question

I have this type of dataset

DF    
     V1     V2     V3
1.   A      AAA    B
2.   BBB    B      CC
3.   C      BB     CCC

And I would like to select the longest string from DF and put it into the new column WINNER like this:

DF    
     V1     V2     V3    WINNER
1.   A      AAA    B     AAA
2.   BBB    B      CC    BBB
3.   C      BB     CCC   CCC

I have tried

mutate( WINNER = select(which.max (c(nchar(V1), nchar(V2), nchar(V3))) 

but it works only for numeric values. I would prefer dplyr solution.

Answer 1

df$winner <- 
  Reduce(function(x, y) ifelse(nchar(y) > nchar(x), y, x), df) 

df
#     V1  V2  V3 winner
# 1:   A AAA   B    AAA
# 2: BBB   B  CC    BBB
# 3:   C  BB CCC    CCC