! grep in R - finding items that do not match [duplicate]

Answer 1

Also, you can try this:

 Key = c(1,2,3,4,5)
Code = c("X348","I605","B777","I609","F123")
df1 <- data.frame(Key, Code)
toRemove<-grep("^I60", df1$Code)
df2 <- df1[-toRemove,]

Answer 2

You could use the [ operator and do

df1[!grepl("I60", Code),]

(Suggested clarification from @Hugh:) Another way would be

df1[!grepl("I60",df1$Code),]

Here is the reference manual on array indexing, which is done with [:

http://cran.r-project.org/doc/manuals/R-intro.html#Array-indexing