R use variable within regex

Question

Okay - maybe this is a better example. I am looking for guidance/references on how to reference a variable within a regex - not how to build a regex for this data.

Answer 1

Try using the paste0() function. That will put together all your variables and any regular expressions you want to use.

grep(paste0("^.*", variable, ".*$"), d1)

you can also add the argument collapse = "" to paste0() if your variable could have >1 element