How to get startsWith function to produce the character instead of the Boolean in R?

Question

As the default, the startsWith function will produce a Boolean output:

x1 <- c("Foobar", "bla bla", "something", "another", "blu", "brown",
        "blau blüht der Enzian")

startsWith(x1, "b")
[1] FALSE  TRUE FALSE FALSE  TRUE  TRUE  TRUE

How can one use it to get the actual names of the words?

Answer 1

For this we can use grep which have the value argument which by default is FALSE

grep("^b", x1, value = TRUE)

Or use the logical vector to subset

x1[startsWith(x1, "b")]