R: find largest common substring starting at the beginning

Question

I\'ve got 2 vectors:

word1 <- \"bestelling\"   
word2 <- \"bestelbon\"

Now I want to find the largest common substring that starts at the

Answer 1

A bit of regex can do this:

sub('^([^|]*)[^|]*(?:\\|\\1[^|]*)$', '\\1', paste0(word1, '|', word2))
#[1] "bestel"

I used | as a separator - pick one that makes sense for your strings.