detecting word boundary with regex in data frame in R

Question

I have a data.frame named all that has a column of factors, these factors include \"word\",\"nonword\" and some others. My goal is to

Answer 1

In R, you need two times \:

grep("\\bword\\b", all[5])

Alternative solutions:

grep("^word$", all[5])

which(all[5] == "word")