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
  • Match everything enclosed
    (?:...)
  • Capture everything enclosed
    (...)
  • 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"
"
gm

Test String

Code Generator

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"(?:(?<=%\()|(?<={))([^\){]*)(?=[}\)])"; string input = @"# Example functions using print that we want to extract the substitution args from def Initialise(self): print '# NDOverlayConfigure(portName, queueSize, blockingCallbacks, NDArrayPort, NDArrayAddr, NOverlays, maxBuffers, maxMemory, priority, stackSize, maxThreads)' print 'NDOverlayConfigure(""%(PORT)s"", %(QUEUE)d, %(BLOCK)d, ""%(NDARRAY_PORT)s"", %(NDARRAY_ADDR)s, %(NOverlays)d, 0, 0, 0, 0, %(MAX_THREADS)d)' % self.__dict__ def Initialise(self): print('# NDROIStatConfigure(portName, queueSize, blockingCallbacks, ' 'NDArrayPort, NDArrayAddr, maxROIs, maxBuffers, maxMemory,' 'priority', 'stackSize', 'maxThreads') print('NDROIStatConfigure(""{PORT}"", {QUEUE}, {BLOCK}, ' '""{NDARRAY_PORT}"", {NDARRAY_ADDR}, {MAX_ROIS}, ' '0, 0, 0, 0, {MAX_THREADS})'.format(**self.__dict__)) def Initialise(self): print '# NDStdArraysConfigure(portName, queueSize, blockingCallbacks, NDArrayPort, NDArrayAddr, maxBuffers, maxMemory, priority, stackSize, maxThreads)' print 'NDStdArraysConfigure(""%(PORT)s"", %(QUEUE)d, %(BLOCK)d, ""%(NDARRAY_PORT)s"", %(NDARRAY_ADDR)s, 0, 0, 0, 0, %(MAX_THREADS)d)' % self.__dict__ "; 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