grep with special characters

Question

I want to find the elements that contains star character in the following vector. ``` s <- c("A","B","C*","D","E*") grep("*",s) [1] 1 2 3 4 5 ``` This is not working. I can understand that since it is a special character. When I read here, I decided to use "\" before star character. But that gave me an error: ``` grep("\*",s) Error: '\*' is an unrecognized escape in character string starting ""\*" ``` What am I doing wrong?

Accepted Answer

You need to escape special characters twice, once for R and once for the regular expression:

```
grep('\*', s)
```

grep with special characters

Solution

Problem