Regular expression definition: It is a model or template for matching strings.
Syntax: The simplest form is to find one or a paragraph. It uses some special characters, such as [*], represents any form of string. [
] Indicates any single string.
Correlated packages and classes of regular expressions in JDK:
Java.util.Regex.pattern: Build a matching model
Java.util.Regex.matcher: Matcher
Steps to use these two classes:
1. Compile your regular expression into the instance of Pattern.
2. Create a Matcher object using the Pattern object.
3. Use the Matcher object to control or manipulate this character sequence.
