Regular Expressions 101

Save & Share

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
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 = @"(?<=gs/).*?(?=""})"; string input = @"[ {""FILENAME"":""/gs/mm-camera-pics/IQ/clark_retasia_ds_df/LX0A3B0143/IMG_20150928_210848118.jpg/L2FwcGhvc3RpbmdfcHJvZC9ibG9icy9BRW5CMlVxelZDdk9MbURfT3BWM2Foay1LUWNhcUdRZUpPM1Izak9CUkpBMGZNWGU5NEJVUWZpbmxkbVFQQ3NGLU1USF9XTEFZN3R3MnhUZHc1SzRQWlZURnVuUHlwQko3Zy41MTE1blJ6SnhMMS1SS3JM""}, {""FILENAME"":""/gs/mm-camera-pics/IQ/merlin_retasia/NCFP130133/IMG_20150928_195315111.jpg/L2FwcGhvc3RpbmdfcHJvZC9ibG9icy9BRW5CMlVvWGRlREo3a2xfTF9lUUhaZUltUWNna09qaVlkeWVtSGlhcDh6RXZGeHQ1SzVvd2hhTUhPQ28yTkpvSml5SU43MVlzQTNudEw1dTl4Q3hoa3ZuNUVjNFVtenNJZy5oTXlkcm5IMTJTdUxPaWlz""}, {""FILENAME"":""/gs/mm-camera-pics/IQ/clark_retasia_ds_df/LX0A3B0143/IMG_20150928_204536530.jpg/L2FwcGhvc3RpbmdfcHJvZC9ibG9icy9BRW5CMlVyX3hnaENKWmdmRGs5SXVaQk5jWUhtelZaWXVtT3VzeXpKSE41ZVF2d3VUQ3I1N3lRSHF5ZDF3aXg1bm51U1QyTmMyUHBFVGYzTzhwQXlKTFV1SFNtRFJNUlZSUS45MG1ZRnVDUks2WDJNb0w1""}, {""FILENAME"":""/gs/mm-camera-pics/IQ/merlin_retasia/NCFP130133/IMG_20150928_195423777.jpg/L2FwcGhvc3RpbmdfcHJvZC9ibG9icy9BRW5CMlVvNVl3cXZjQmNBSHowVW83SVVyVzYtM0hDOUhCS3hYandVWkVTYUNaTkViUHdYSHVRVFRHQzNsNWhhVEZrVzQtTThnZTJwb05HVVI2ZFA5aFh0ck82ZlFXQjluUS5pM2FldmFFRkJ2bWR3cGJu""}, {""FILENAME"":""/gs/mm-camera-pics/IQ/clark_retasia_ds_df/LX0A3B0143/IMG_20150928_204725016.jpg/L2FwcGhvc3RpbmdfcHJvZC9ibG9icy9BRW5CMlVvQWdvYmJBYlM1am9ZWU1nOHdPYnZEUWFlTEk3cC1uTmxmRF9PMHhBM0ZDRjByNy1WMTc1QUlXbi1TN3I2MjFFSlBERWpJbWdkMnYyOVpQdFlrM183OUJrWG1IUS5GVVhoX3lVTGJtMmNYZEVM""}, {""FILENAME"":""/gs/mm-camera-pics/IQ/merlin_retasia/NCFP130133/IMG_20150928_210737525.jpg/L2FwcGhvc3RpbmdfcHJvZC9ibG9icy9BRW5CMlVxV1RWTjBxSlNPT1VCejc5eXk0R0xuUElFYlRfX25OQTdLcHZoUk44MWZpTnR2TW1aSldLTHlOeDFXeVZOY0Y2c2kzNmIxZ2Q5RGE0Zm9mTGZkSWJIa1VOdUFiQS5nWDZFMk9MZTdsN0tpeGJN""}, {""FILENAME"":""/gs/mm-camera-pics/IQ/merlin_retasia/NCFP130133/IMG_20150928_185044623.jpg/L2FwcGhvc3RpbmdfcHJvZC9ibG9icy9BRW5CMlVvZzFIY1Bub0ZjNW0xdEx0M3gyd2xIcUVYUVBhT3VLOXlpVEVsYTVVQTdWRDdWS3RuRUU2TVhTWXJZN1pORE5ScXFGZHY3bi1kSmFCZ0t4eDItblFVbTBSVHFHUS56amIyUTRPY3FYZnhyVmZZ""}, {""FILENAME"":""/gs/mm-camera-pics/IQ/merlin_retasia/NCFP130133/IMG_20150928_184936345.jpg/L2FwcGhvc3RpbmdfcHJvZC9ibG9icy9BRW5CMlVxS0hlV3lUSnpkYTZFWGRManZUWXoyNmRVTkFwUFlEU2ExTnZXSmFScUhPOHRLX3NVek53WWZCMGhwbUc5bk55eDEwNFdsY3RxTGpXV3BIV293U0d6cDFiakxvZy5pSmowNjFtWWFQQ2kxSDVy""}, {""FILENAME"":""/gs/mm-camera-pics/IQ/clark_retasia_ds_df/LX0A3B0143/IMG_20150928_210850868.jpg/L2FwcGhvc3RpbmdfcHJvZC9ibG9icy9BRW5CMlVxaklHS3BKN1F3VUt1NWhqUkZ5ekU0cXFyQVAwNEc3TGZqSVd2c19WeDMxYk1vazVoVzhSVy1vVXdxMFE1c2ZWWS14VDlhVXp4S1N6dElsMW5YcldOYnBtckx5QS5rZEdWRUx2YjJuRXZOTlh3""}, {""FILENAME"":""/gs/mm-camera-pics/IQ/merlin_retasia/NCFP130133/IMG_20150928_195420733.jpg/L2FwcGhvc3RpbmdfcHJvZC9ibG9icy9BRW5CMlVwRUNaanhBVnMtVDFwbFhoeUNEcGhJbEhsMWk1VWtPUlJyX2hETWxJRGhUbFF4dTh5SVlac0pnaUV6cTFsWjZFaHVuRC1qWWxSWE8wV2pVSzFfNUhodk0xazBwUS4taE5Cc1FFdnRKTDFtaWMz""} ]"; 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