regex - Regular expression that both includes and excludes certain strings in R

Question

I am trying to use R to parse through a number of entries. I have two requirements for the the entries I want back. I want all the entries that contain the word apple but don't contain the word orange.

For example:

1. I like apples
2. I really like apples
3. I like apples and oranges

I want to get entries 1 and 2 back.

How could I go about using R to do this?

Thanks.

Answer 1

Could do

temp <- c("I like apples", "I really like apples", "I like apples and oranges")
temp[grepl("apple", temp) & !grepl("orange", temp)]

## [1] "I like apples"      "I really like apples"