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

r"
"
g

Test String

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"(?<=src=\\"").*?(?=\\"")"; string input = @"{""Items"":[{""ItemID"":10198,""ItemType"":null,""Subject"":null,""SubjectID"":14,""Area"":null,""AreaID"":18,""Topic"":null,""TopicID"":18,""SubTopicID"":0,""ItemBankName"":null,""Direction"":"",""ItemTitle"":""Q.53"",""IsApproved"":false,""Item"":""\u003cp\u003e\u003cspan style=\""font-size: 14.7px;\""\u003eThe\u003c/span\u003e\u003cspan style=\""font-size: 14.7px;\""\u003e efficiency of the screw\u0026nbsp;\u003c/span\u003e\u003cspan style=\""font-size: 14.7px;\""\u003ein %\u0026nbsp;\u003c/span\u003e\u003cspan style=\""font-size: 14.7px;\""\u003eupto\u003c/span\u003e\u003cspan style=\""font-size: 14.7px;\""\u003e two decimal places is\u0026nbsp;\u003c/span\u003e\u003cspan style=\""font-size: 14.7px;\""\u003e[quizky-text]\u003c/span\u003e\u003c/p\u003e"",""ItemPassageID"":352,""Passage"":""\u003cp\u003e\u003cstrong\u003e\u003cspan style=\""font-size: 14.7px;\""\u003eStatement\u003c/span\u003e\u003cspan style=\""font-size: 14.7px;\""\u003e for Linked Answer Questions 52 and 53:\u0026nbsp;\u003c/span\u003e\u003c/strong\u003e\u003cbr /\u003e \u003cspan style=\""font-size: 14.7px;\""\u003eA load of 30 KN is raised by means of a screw jack having square threaded screw of pitch 12 mm. The spindle diameter is 50 mm. If a force of 350 N is applied at the end of a lever to raise the load, co-efficient of friction\u0026nbsp;\u003c/span\u003e\u003cspan style=\""font-size: 14.7px;\""\u003eis\u003c/span\u003e\u003cspan style=\""font-size: 14.7px;\""\u003e 0.15.\u003c/span\u003e\u003c/p\u003e"",""PassageTitle"":null,""IsLinkedQuestion"":false,""Points"":0,""Explanation"":""\u003cp\u003e\u003cspan style=\""font-family: Symbol;\""\u003eh\u003c/span\u003e\u003cspan style=\""font-size: 14.7px;\""\u003e =\u0026nbsp;\u003c/span\u003e\u003cimg style=\""vertical-align: bottom;\"" src=\""QUIZKYIMAGEREPO/docximg_1128711867_image197.png\"" alt=\""\"" width=\""54\"" height=\""32\"" data-docx-image=\""image197.emf\"" /\u003e\u003cspan style=\""font-size: 14.7px;\""\u003e =\u0026nbsp;\u003c/span\u003e\u003cimg style=\""vertical-align: bottom;\"" src=\""QUIZKYIMAGEREPO/docximg_1128711867_image198.png\"" alt=\""\"" width=\""40\"" height=\""31\"" data-docx-image=\""image198.emf\"" /\u003e\u003cspan style=\""font-size: 14.7px;\""\u003e = 33%\u003c/span\u003e\u003c/p\u003e"",""ItemBankID"":0,""LOD"":null,""LODID"":2,""ItemBank"":0,""QuestionPaper"":0,""IsProofRead"":false,""CorrectIndex"":0,""QuestionPaperSectionID"":0,""ItemOptionModel"":null}],""ItemOptions"":[{""ItemOptionID"":37637,""ItemID"":0,""Option"":""\u003cp\u003e\u003cspan style=\""font-family: Arial; font-size: 12px;\""\u003e\u0026nbsp;\u003c/span\u003e\u003cspan style=\""font-family: Arial; font-size: 12px;\""\u003e33.36\u003c/span\u003e\u003c/p\u003e"",""RHSOption"":null,""MarkedIndex"":null,""OrderNumber"":null,""OptionIndex"":0,""IsCorrect"":false,""IsHTML"":false,""RHSIsHTML"":false,""ColumnID"":0},{""ItemOptionID"":37638,""ItemID"":0,""Option"":""\u003cp\u003e\u003cspan style=\""font-family: Arial; font-size: 12px;\""\u003e\u0026nbsp;\u003c/span\u003e\u003cspan style=\""font-family: Arial; font-size: 12px;\""\u003e33.36\u003c/span\u003e\u003c/p\u003e"",""RHSOption"":null,""MarkedIndex"":null,""OrderNumber"":null,""OptionIndex"":0,""IsCorrect"":false,""IsHTML"":false,""RHSIsHTML"":false,""ColumnID"":0}]}"; foreach (Match m in Regex.Matches(input, pattern)) { 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