What is a Regular Expression?
A regular expression is a sequence of characters that forms a search pattern. When you search for data in a text, you can use this search pattern to describe what you are searching for.
A regular expression can be a single character, or a more complicated pattern.
Regular expressions can be used to perform all types of text search and text replace operations.
Java does not have a built-in Regular Expression class, but we can import the java.util.regex package to work with regular expressions. The package includes the following classes:
PatternClass – Defines a pattern (to be used in a search)MatcherClass – Used to search for the patternPatternSyntaxExceptionClass – Indicates syntax error in a regular expression pattern