How to extract strings using regular expressions in R language?

In R language, the gsub() function can be used to extract strings.
Here is an example:

string <- "Hello, my name is John."
pattern <- "name is (\\w+)"
result <- gsub(pattern, "\\1", string)
print(result)

In this example, we want to extract the name from a string. We are using a regular expression with the pattern set to “name is (\w+)”, where “(\w+)” represents one or more letter characters. Then, we use the gsub() function to replace the matched pattern with the matched substring, which is the name. During the replacement process, we use “\1” to reference the first capture group in the regular expression. Finally, we print out the result.

The output result is “John”.