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

/
/
gm

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"<([a-zA-Z\d]+?)([^<>]|(?!.*href).*)>([^<>]*?)(小编)([^<>]*?)(<\/\1>)"; string substitution = @"<$1$2>$3<a href=""{link}"" target=""_blank"">$4</a>$5$6'"; string input = @"<p> <link rel=""stylesheet"" href=""/public/lib/froala/css/froala_style.min.css""> </p> <span>高校在线教学国际平台建设启动？这是怎么回事呢？下面就跟小编一起来了解一下事情的始末吧！</span> <a href="">高校在线教学国际平台建设启动？这是怎么回事呢？下面就跟小编一起来了解一下事情的始末吧！</a> <p><span style='color: rgb(34, 34, 34); font-family: Consolas, ""Lucida Console"", ""Courier New"", monospace; font-size: 12px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: left; text-indent: 0px; text-transform: none; white-space: pre-wrap; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;'>高校在线教学国际平台建设启动？这是怎么回事呢？下面就跟小编一起来了解一下事情的始末吧！</span>&nbsp;</p> <span style='color: rgb(34, 34, 34); font-family: Consolas, ""Lucida Console"", ""Courier New"", monospace; font-size: 12px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: left; text-indent: 0px; text-transform: none; white-space: pre-wrap; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-style: initial; text-decoration-color: initial; display: inline !important; float: none;'>以上就是小编给大家分享的相关情况介绍，希望对大家有所帮助！最后，小编送大家一句话：当许多人在一条路上徘徊不前时，他们不得不让开一条大路，让那珍惜时间的人赶到他们的前面去。&mdash;&mdash;苏格拉底</span>"; RegexOptions options = RegexOptions.Multiline; Regex regex = new Regex(pattern, options); string result = regex.Replace(input, substitution); } }

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