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

/
/
gis

Test String

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"<(?:textarea|select).*?>.*?(\{\{\{variable:(.*?)\}\}\}).*?<\/(?:textarea|select)>|<(?:input).+?(value=.*?)(\{\{\{variable:(.+?)\}\}\})?.*?>|(\{\{\{variable:(.*?)\}\}\})"; string input = @" <section id=""services""> <div class=""container""> <div class=""row""> <div class=""col-md-12""> <p>You are using system version: {{{variable:system_version}}}</p> <p>Your address: {{{variable:contact-email-address}}}</p> <form action=""http://k.loc/content/view/welcome"" class=""default-form"" enctype=""multipart/form-data"" method=""post"" accept-charset=""utf-8""> <input type=""hidden"" name=""csrfkcmstoken"" value=""94ee71ada809b9a79d1b723c81020c78"" /> <div class=""row""> <div class=""col-sm-12 form-error""></div> </div> <div class=""row""><div class=""col-sm-12""><fieldset id=""personalinfo""><legend>Personal information</legend><div class=""row""><div class=""col-sm-12""> <div class=""control-label""> <label for=""testinput"">Name<span class=""form-validation-required""> * </span></label> </div> <div class=""hint-text"">Enter at least 2 characters and a maximum of 12 characters.</div><input id=""testinput"" name=""testinput"" placeholder=""Enter your name here."" class=""input-group width-50"" type=""text"" value=""{{{variable:system_name}}} {{{variable:system_login}}}""><div class=""row""><div class=""col-sm-12""><div class=""form-error""></div></div></div></div></div><div class=""row""><div class=""col-sm-12""> <div class=""control-label""> <label for=""testpassword"">Password</label> </div> <div class=""hint-text"">Your password must be at least 12 characters long, contain 1 special character, 1 nunber, 1 lower case character and 1 upper case character.</div><input id=""testpassword"" name=""testpassword"" placeholder=""Enter your password here."" class=""input-group width-50"" type=""password""><div class=""row""><div class=""col-sm-12""><div class=""form-error""></div></div></div></div></div></fieldset></div></div><div class=""row""><div class=""col-sm-12""><fieldset id=""bioinfo""><legend>Biographical information</legend><div class=""row""><div class=""col-sm-12""> <div class=""control-label""> <label for=""testtextarea"">Biography</label> <span class=""hint-text"">A minimum of 40 characters and a maximum of 255 is allowed. This hint is displayed inline.</span> </div> <textarea id=""testtextarea"" name=""testtextarea"" placeholder=""Please enter your biography here."" class=""input-group-wide width-100"" rows=""5"" cols=""80"">{{{variable:system_name}}} {{{variable:system_login}}}</textarea><div class=""row""><div class=""col-sm-12""><div class=""form-error""></div></div></div></div></div><div class=""row""><div class=""col-sm-12""> <div class=""control-label""> <label for=""testsummernote"">Interests</label> <span class=""hint-text"">A minimum of 40 characters is required. This hint is displayed inline.</span> </div> <textarea id=""testsummernote"" name=""testsummernote"" class=""wysiwyg-editor"" placeholder=""Please enter your interests here.""><p>{{{variable:system_name}}}<br></p><p>{{{variable:system_login}}}</p><p>{{{variable:activate_url}}}<br></p></textarea></div></div></fieldset></div></div><div class=""row""><div class=""col-sm-12""><button name=""testsubmit"" id=""testsubmit"" type=""submit"" class=""btn primary"">Submit<i class=""zmdi zmdi-arrow-forward""></i></button></div></div> </form> </div> "; RegexOptions options = RegexOptions.IgnoreCase | RegexOptions.Singleline; 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