r - First entry from string split

Question

I've got a column people$food that has entries like chocolate or apple-orange-strawberry.

I want to split people$food by - and get the first entry from the split.

In python, the solution would be food.split('-')[0], but I can't find an equivalent for R.

Answer 1

If you need to extract the first (or nth) entry from each split, use:

word <- c('apple-orange-strawberry','chocolate')

sapply(strsplit(word,"-"), `[`, 1)
#[1] "apple"     "chocolate"

Or faster and more explictly:

vapply(strsplit(word,"-"), `[`, 1, FUN.VALUE=character(1))
#[1] "apple"     "chocolate"

Both bits of code will cope well with selecting whichever value in the split list, and will deal with cases that are outside the range:

vapply(strsplit(word,"-"), `[`, 2, FUN.VALUE=character(1))
#[1] "orange" NA