R grep pattern regex with brackets

Question

I have a problem with grep in R:

patterns= c("AB_(1)","AB_(2)") text= c("AB_(1)","DDD","CC")  grep(patterns[1],text) >integer(0)  ???? 

the grep command has problem with "()" brackets, is there any as.XX(patterns[1]) that I can use??

Answer 1

You need escape by double backslash:

> patterns= c("AB_\\(1\\)","AB_(2)") > text= c("AB_(1)","DDD","CC") >  > grep(patterns[1],text) [1] 1