Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

~
~
g

Test String

Code Generator

Language

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "\\[#](.*?)\\)"; final String string = "# [#](http://heavy_code_industry.gitee.io/code_heavy_industry/pro002-maven/chapter05/#第五章-其他核心概念)第五章 其他核心概念\n\n" + "## [#](http://heavy_code_industry.gitee.io/code_heavy_industry/pro002-maven/chapter05/#_1、生命周期)1、生命周期\n\n" + "### [#](http://heavy_code_industry.gitee.io/code_heavy_industry/pro002-maven/chapter05/#_1作用)①作用\n\n" + "为了让构建过程自动化完成，Maven 设定了三个生命周期，生命周期中的每一个环节对应构建过程中的一个操作。\n\n" + "### [#](http://heavy_code_industry.gitee.io/code_heavy_industry/pro002-maven/chapter05/#_2三个生命周期)②pile 编译测试源代码。 process-test-classes test 使用合适的单元测试框架运行测试。这些测试代码不会被打包或部署。 prepare-package package 接受编译好的代码，打包成可发布的格式，如JAR。 pre-integration-test integration-test post-integration-test verify install将包安装至本地仓库，以让其它项目依赖。 deploy将最终的包复制到远程的仓库，以让其它开发人员共享；或者部署到服务器上运行（需借助插件，例如：cargo）。 |\n\n" + "### [#](http://heavy_code_industry.gitee.io/code_heavy_industry/pro002-maven/chapter05/#_3特点)③特点\n\n" + "- 前面三个生命周期彼此是独立的。\n" + "- 在任何一个生命周期内部，执行任何一个具体环节的操作，都是从本周期最初的位置开始执行，直到指定的地方。（本节记住这句话就行了，其他的都不需要记）\n\n" + "Maven 之所以这么设计其实就是为了提高构建过程的自动化程度：让使用者只关心最终要干的即可，过程中的各个环节是自动执行的。\n\n" + "## [#](http://heavy_code_industry.gitee.io/code_heavy_industry/pro002-maven/chapter05/#_2、插件和目标)2、插件和目标\n\n" + "### [#](http://heavy_code_industry.gitee.io/code_heavy_industry/pro002-maven/chapter05/#_1插件)①插件\n"; final Pattern pattern = Pattern.compile(regex); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(i)); } } } }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html