Pattern matching is the process of searching text to identify matches, or strings that match a regex’s pattern. Java supports pattern matching via its Regex API.

The Java pattern-matching engine and backtracking The java.util.regex package uses a type of pattern-matching engine called a Nondeterministic Finite Automaton, or NFA.

Our regular expression thus matches a word, followed by one or more whitespace characters, followed by a second instance of the word. The trailing word boundary sequence (\) is necessary to prevent ...