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
Processing...

Test String

Substitution
Processing...

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"<outcomeDeclaration(.*?)\/>"; string substitution = @"<outcomeDeclaration$1>\n\t<defaultValue>\n\t\t<value>0</value>\n\t</defaultValue>\n</outcomeDeclaration>"; string input = @"<assessmentItem xmlns=""http://www.imsglobal.org/xsd/imsqti_v2p1"" xmlns:m=""http://www.w3.org/1998/Math/MathML"" xmlns:xi=""http://www.w3.org/2001/XInclude"" xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"" xsi:schemaLocation=""http://www.imsglobal.org/xsd/imsqti_v2p1 http://www.imsglobal.org/xsd/qti/qtiv2p1/imsqti_v2p1.xsd"" identifier=""IT0000300"" title=""IT0000300"" label=""Item Label"" adaptive=""false"" timeDependent=""false"" toolName=""TAO"" toolVersion=""3.1.0-sprint23""> <responseDeclaration identifier=""_64B7CBD9-8ED4-EC27-D190-BD0751A38A95"" cardinality=""single"" baseType=""string""/> <outcomeDeclaration identifier=""SCORE"" cardinality=""single"" baseType=""float""> <defaultValue> <value>0</value> </defaultValue> </outcomeDeclaration> <outcomeDeclaration identifier=""SCORE"" cardinality=""single"" baseType=""float""/> <stylesheet href=""style/custom/tao-user-styles.css"" type=""text/css"" media=""all"" title=""/> <itemBody> <div class=""grid-row""> <div class=""col-12""><prompt> <p>300</p> </prompt> <extendedTextInteraction responseIdentifier=""_64B7CBD9-8ED4-EC27-D190-BD0751A38A95"" base=""10"" minStrings=""0"" format=""plain"" class=""> </extendedTextInteraction> </div> </div> </itemBody>"; Regex regex = new Regex(pattern); 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