Regular Expressions 101

Save & Share

  • Regex Version: ver. 1
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

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

/
/
si

Test String

Code Generator

Language

Generated Code

# coding=utf8 # the above tag defines encoding for this document and is for Python 2.x compatibility import re regex = r"\".*?(hotelscombined\.com).*?\"" test_str = "<p>We had original plans to stop in <strong>Savannah</strong> for a night, but it was so close to Charleston that we decided to just top there for a few hours for lunch and a look and then drive the other few hours to Jacksonville.</p> <p>We started fairly late in the morning as we took the kids to a playground to expend their energy first thing in the morning. After half an hour of so of playing pirates we all jumped into the car to Savannah.</p> <p>In Savannah <strong>we ate at the coolest Pirate House restaurant</strong> that was built in the 1700�s. We posted a postcard and then bounced back into our mini van for the drive to <strong>Jacksonville</strong>.</p> <p>Drive was pretty uneventful with one amazing bridge and crossing over the border into Florida was exciting too.</p> <p>We realized we�d <a title=\"Where to stay when you are road tripping East Coast USA\" href=\"/\">booked a hotel at the actual airport</a>, but it was super cheap and had nearby food so we ate, then put the kids to bed. <em><a href=\"http://www.hotelscombined.com/Hotel/Jacksonville_Airport_Hotel.htm\" target=\"_blank\">For the latest prices at the Hilton click here. </a></em></p> <p><img style=\"display: block; margin-left: auto; margin-right: auto;\" src=\"/files/\" alt=\"DSC07623.jpg\" width=\"700\" height=\"465\" /></p> <p> </p>" matches = re.search(regex, test_str, re.DOTALL | re.IGNORECASE) if matches: print ("Match was found at {start}-{end}: {match}".format(start = matches.start(), end = matches.end(), match = matches.group())) for groupNum in range(0, len(matches.groups())): groupNum = groupNum + 1 print ("Group {groupNum} found at {start}-{end}: {group}".format(groupNum = groupNum, start = matches.start(groupNum), end = matches.end(groupNum), group = matches.group(groupNum))) # Note: for Python 2.7 compatibility, use ur"" to prefix the regex and u"" to prefix the test string and substitution.

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 Python, please visit: https://docs.python.org/3/library/re.html