Regular Expressions 101

Save & Share

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
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

`
`
gm

Test String

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"(?s:(""name"" : ""(.*?)"".*?作者[:]*</span>[:]*.*?>(.*?)<.*?出版社.*?> (.*?)<.*?>出版年.*?([\d]{4}-[\d]).*?定价:</span> (.*?)<.*?ISBN:</span> (.*?)<.*?v:average""> ([\d].[\d]).*?v:votes"">([\d]+?)<.*?""rating_per"">(.*?)<.*?""rating_per"">(.*?)<.*?""rating_per"">(.*?)<.*?""rating_per"">(.*?)<.*?""rating_per"">(.*?)<))"; string input = @" <script type=""application/ld+json""> { ""@context"":""http://schema.org"", ""@type"":""Book"", ""workExample"": [], ""name"" : ""索拉里斯星"", <span class=""pl""> 作者</span>: <a class="" href=""/search/%E6%96%AF%E5%9D%A6%E5%B0%BC%E6%96%AF%E7%93%A6%E5%A4%AB%C2%B7%E8%8E%B1%E5%A7%86"">[波] 斯坦尼斯瓦夫·莱姆</a> </span><br/> <span class=""pl"">出版社:</span> 译林出版社<br/> <span class=""pl"">原作名:</span> Solaris<br/> <span> <span class=""pl""> 译者</span>: <a class="" href=""/search/%E9%9D%96%E6%8C%AF%E5%BF%A0"">靖振忠</a> </span><br/> <span class=""pl"">出版年:</span> 2021-8<br/> <span class=""pl"">页数:</span> 254<br/> <span class=""pl"">定价:</span> 49.00元<br/> <span class=""pl"">装帧:</span> 平装<br/> <span class=""pl"">丛书:</span>&nbsp;<a href=""https://book.douban.com/series/54333"">译林幻系列</a><br> <span class=""pl"">ISBN:</span> 9787544782173<br/> </div> </div> <div id=""interest_sectl"" class=""> <div class=""rating_wrap clearbox"" rel=""v:rating""> <div class=""rating_logo"">豆瓣评分</div> <div class=""rating_self clearfix"" typeof=""v:Rating""> <strong class=""ll rating_num "" property=""v:average""> 8.7 </strong> <span property=""v:best"" content=""10.0""></span> <div class=""rating_right ""> <div class=""ll bigstar45""></div> <div class=""rating_sum""> <span class=""> <a href=""comments"" class=""rating_people""><span property=""v:votes"">8085</span>人评价</a> </span> </div> </div> </div> <span class=""stars5 starstop"" title=""力荐""> 5星 </span> <div class=""power"" style=""width:64px""></div> <span class=""rating_per"">46.0%</span> <br> <span class=""stars4 starstop"" title=""推荐""> 4星 </span> <div class=""power"" style=""width:54px""></div> <span class=""rating_per"">39.4%</span> <br> <span class=""stars3 starstop"" title=""还行""> 3星 </span> <div class=""power"" style=""width:17px""></div> <span class=""rating_per"">12.5%</span> <br> <span class=""stars2 starstop"" title=""较差""> 2星 </span> <div class=""power"" style=""width:2px""></div> <span class=""rating_per"">1.8%</span> <br> <span class=""stars1 starstop"" title=""很差""> 1星 </span> <div class=""power"" style=""width:0px""></div> <span class=""rating_per"">0.3%</span> "; RegexOptions options = RegexOptions.Multiline; foreach (Match m in Regex.Matches(input, pattern, options)) { Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index); } } }

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 C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx