alphanumeric regular expression in R

Question

I am trying to use [:alnum:] as explained on ?regex

Anyone knows why

grepl(\"^([a-zA-Z0-9])+([;])\", x=\"dj5sads;adsa\")

returns TRU

Answer 1

what you want is

grepl("^([[:alnum:]])+([;])", x="dj5sads;adsa")    

remember we put the SearchPattern