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

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"(?<=\""text\"": \"")(.*?hello.*?)(?="", \""type\"": \""text\"")"; string input = @"{""root"": {""type"": ""root"", ""format"": "", ""indent"": 0, ""version"": 1, ""children"": [{""type"": ""paragraph"", ""format"": "", ""indent"": 0, ""version"": 1, ""children"": [{""mode"": ""normal"", ""text"": ""text1 hello text"", ""type"": ""text"", ""style"": "", ""detail"": 0, ""format"": 0, ""version"": 1}], ""direction"": ""ltr""}], ""direction"": ""ltr""}} hellocat world f {""root"": {""type"": ""root"", ""format"": "", ""indent"": 0, ""version"": 1, ""children"": [{""type"": ""paragraph"", ""format"": "", ""indent"": 0, ""version"": 1, ""children"": [{""src"": ""https://images.unsplash.com/photo-1458966480358-a0ac42de0a7a?crop=entropy&cs=tinysrgb&fit=max&fm=jpg&ixid=M3w1MjU5NTl8MHwxfHNlYXJjaHwzfHx0cmVlfGVufDB8fHx8MTcxMzk5MjE4OHww&ixlib=rb-4.0.3&q=80&w=1080"", ""type"": ""image"", ""width"": 332, ""height"": ""221.329875"", ""version"": 1, ""alt_text"": ""image"", ""max_width"": 500}, {""mode"": ""normal"", ""text"": ""dsadsa"", ""type"": ""text"", ""style"": "", ""detail"": 0, ""format"": 0, ""version"": 1}], ""direction"": ""ltr""}, {""type"": ""paragraph"", ""format"": "", ""indent"": 0, ""version"": 1, ""children"": [{""mode"": ""normal"", ""text"": ""fdsfds"", ""type"": ""text"", ""style"": "", ""detail"": 0, ""format"": 0, ""version"": 1}], ""direction"": ""ltr""}], ""direction"": ""ltr""}} {""root"": {""type"": ""root"", ""format"": "", ""indent"": 0, ""version"": 1, ""children"": [{""type"": ""paragraph"", ""format"": "", ""indent"": 0, ""version"": 1, ""children"": [{""mode"": ""normal"", ""text"": ""nccccchello ddddd"", ""type"": ""text"", ""style"": "", ""detail"": 0, ""format"": 0, ""version"": 1}], ""direction"": ""ltr""}], ""direction"": ""ltr""}} {""root"": {""type"": ""root"", ""format"": "", ""indent"": 0, ""version"": 1, ""children"": [{""tag"": null, ""type"": ""paragraph"", ""start"": null, ""format"": "", ""indent"": 0, ""version"": 1, ""children"": [{""rel"": null, ""src"": null, ""url"": null, ""mode"": ""normal"", ""text"": ""bvcbvc"", ""type"": ""text"", ""style"": "", ""title"": null, ""value"": null, ""width"": null, ""detail"": 0, ""format"": 0, ""height"": null, ""indent"": null, ""inline"": null, ""target"": null, ""checked"": null, ""version"": 1, ""alt_text"": null, ""children"": null, ""equation"": null, ""field_id"": null, ""direction"": null, ""max_width"": null, ""field_name"": null, ""field_type"": null, ""highlight_type"": null, ""hidden_field_name"": null, ""hidden_field_value"": null}], ""language"": null, ""video_id"": null, ""direction"": ""ltr"", ""list_type"": null}], ""direction"": ""ltr""}} {""root"": {""type"": ""root"", ""format"": "", ""indent"": 0, ""version"": 1, ""children"": [{""tag"": null, ""type"": ""paragraph"", ""start"": null, ""format"": "", ""indent"": 0, ""version"": 1, ""children"": [{""rel"": null, ""src"": null, ""url"": null, ""mode"": ""normal"", ""text"": ""gbfbvc"", ""type"": ""text"", ""style"": "", ""title"": null, ""value"": null, ""width"": null, ""detail"": 0, ""format"": 0, ""height"": null, ""indent"": null, ""inline"": null, ""target"": null, ""checked"": null, ""version"": 1, ""alt_text"": null, ""children"": null, ""equation"": null, ""field_id"": null, ""direction"": null, ""max_width"": null, ""field_name"": null, ""field_type"": null, ""highlight_type"": null, ""hidden_field_name"": null, ""hidden_field_value"": null}], ""language"": null, ""video_id"": null, ""direction"": ""ltr"", ""list_type"": null}], ""direction"": ""ltr""}}"; 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