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 = @"(-----BEGIN PUBLIC KEY-----(\n|\r|\r\n)([0-9a-zA-Z\+\/=]{64}(\n|\r|\r\n))*([0-9a-zA-Z\+\/=]{1,63}(\n|\r|\r\n))?-----END PUBLIC KEY-----)|(-----BEGIN PRIVATE KEY-----(\n|\r|\r\n)([0-9a-zA-Z\+\/=]{64}(\n|\r|\r\n))*([0-9a-zA-Z\+\/=]{1,63}(\n|\r|\r\n))?-----END PRIVATE KEY-----)"; string input = @"-----BEGIN PRIVATE KEY----- MIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEAwghnvMu5YfnbprpLX105 SGuanX7zF+4mgNqozyFB7UsIha3ztQIYydrLc7pKXK7vQWWlqLUn0JW1vlAiTs2A O+wdaFaEwKTNk1+mobGlpKUrzJEy24cnGV9XxNnh+WuxR7TicEpzNOdmDnSUaFMk MdfpDXKKXfu/HJrADYuMq7VckEBR1yOBXVREDYpS8YvA85Kw04VAPVzxOHU7qdTR hUPUD1rY3nKYJj33P0EW1e53xqeXZiiW6p3yi04X+OQscylMnfvxsG8tK18Qgi30 cQmny3yYGocKpfG7679Jy5EnkchqoC9L72Ust8A6s0WZVAe/bZxs5J5QEDdAkgAi Miw84vWIHj2cuwgNKzBJHZ1uHmFrM8rkJWBvLyTRvS1pgn/yjQ4evOTH/yVTGnyM BOSwrXmFbt4KXzXwtXIf0wllf2HZ3CwhB9g86ijPjvvgXn8eUbBEN12c/MePf3l1 doECe6oavsthqpk77IuFC6Yuy5ck0fkcHT2cw/U6hUBdTbuXs4/i7gMLE9VpjiDh lYoMCYmuCR8Vn/G5gMQ4NbMjyvZY/d5U8tvktsC2ImQefuWu8vi/PGvDIdhq3TTz sswoxcLxyqq0vjOnBmpMpua2PpLlZrSuBkuKIuZnxAiRkkLamAVH6SylYwmWvvam ssssss1 -----END PRIVATE KEY----- -----BEGIN PUBLIC KEY----- MIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEAwghnvMu5YfnbprpLX105 SGuanX7zF+4mgNqozyFB7UsIha3ztQIYydrLc7pKXK7vQWWlqLUn0JW1vlAiTs2A O+wdaFaEwKTNk1+mobGlpKUrzJEy24cnGV9XxNnh+WuxR7TicEpzNOdmDnSUaFMk MdfpDXKKXfu/HJrADYuMq7VckEBR1yOBXVREDYpS8YvA85Kw04VAPVzxOHU7qdTR hUPUD1rY3nKYJj33P0EW1e53xqeXZiiW6p3yi04X+OQscylMnfvxsG8tK18Qgi30 cQmny3yYGocKpfG7679Jy5EnkchqoC9L72Ust8A6s0WZVAe/bZxs5J5QEDdAkgAi Miw84vWIHj2cuwgNKzBJHZ1uHmFrM8rkJWBvLyTRvS1pgn/yjQ4evOTH/yVTGnyM BOSwrXmFbt4KXzXwtXIf0wllf2HZ3CwhB9g86ijPjvvgXn8eUbBEN12c/MePf3l1 doECe6oavsthqpk77IuFC6Yuy5ck0fkcHT2cw/U6hUBdTbuXs4/i7gMLE9VpjiDh lYoMCYmuCR8Vn/G5gMQ4NbMjyvZY/d5U8tvktsC2ImQefuWu8vi/PGvDIdhq3TTz sswoxcLxyqq0vjOnBmpMpua2PpLlZrSuBkuKIuZnxAiRkkLamAVH6SylYwmWvvam ssssssqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqs -----END PUBLIC KEY-----"; 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