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

/
/
g

Test String

Code Generator

Language

Generated Code

use strict; my $str = ' top="241" left="79" width="105" height="7" font="3">InnerSpace - InnerSpace: Top </text> top="250" left="79" width="97" height="7" font="3">25 Sexy Sci-Fi Stars 2015 (0)</text> top="259" left="79" width="27" height="7" font="3">HD CC[]</text> top="268" left="79" width="27" height="7" font="3">EXEMPT</text> top="286" left="79" width="95" height="10" font="4">InnerSpace - - (208)</text> top="299" left="79" width="38" height="10" font="4">HD CC[]</text> top="311" left="79" width="38" height="10" font="4">EXEMPT</text> top="331" left="80" width="85" height="12" font="2">Being Human - </text> top="345" left="80" width="85" height="12" font="2">Cheater of The </text> top="359" left="80" width="44" height="12" font="2">Pack (6)</text> top="374" left="80" width="63" height="12" font="2">HD CC DV[]</text> top="388" left="80" width="22" height="12" font="2">14+</text> top="419" left="80" width="107" height="12" font="2">Star Trek: Voyager </text> top="434" left="80" width="103" height="12" font="2">- Flesh And Blood, </text> <text top="90" left="386" width="166" height="11" font="1"><b>03-AUG-2015 to 09-AUG-2015</b></text> <text top="152" left="37" width="31" height="11" font="1"><b>06:00</b></text> <text top="240" left="37" width="31" height="11" font="1"><b>07:00</b></text> <text top="329" left="37" width="31" height="11" font="1"><b>08:00</b></text> <text top="115" left="108" width="63" height="13" font="0"><b>Monday </b></text> <text top="131" left="111" width="45" height="13" font="0"><b>Aug 03</b></text> <text top="76" left="449" width="41" height="11" font="1"><b>SPACE</b></text> <text top="117" left="324" width="67" height="11" font="1"><b>Wednesday</b></text> <text top="131" left="337" width="40" height="11" font="1"><b>Aug 05</b></text> <text top="115" left="439" width="65" height="13" font="0"><b>Thursday </b></text> <text top="131" left="447" width="45" height="13" font="0"><b>Aug 06</b></text> <text top="115" left="561" width="52" height="13" font="0"><b>Friday </b></text> <text top="131" left="558" width="45" height="13" font="0"><b>Aug 07</b></text> <text top="115" left="664" width="62" height="13" font="0"><b>Saturday </b></text> <text top="131" left="670" width="45" height="13" font="0"><b>Aug 08</b></text> <text top="115" left="780" width="60" height="13" font="0"><b>Sunday </b></text> <text top="131" left="782" width="45" height="13" font="0"><b>Aug 09</b></text>'; my $regex = qr/\s+top="\d{1,}".*><b>'.$enDayNames.'\s+\D+<\/b>/p; if ( $str =~ /$regex/g ) { print "Whole match is ${^MATCH} and its start/end positions can be obtained via \$-[0] and \$+[0]\n"; # print "Capture Group 1 is $1 and its start/end positions can be obtained via \$-[1] and \$+[1]\n"; # print "Capture Group 2 is $2 ... and so on\n"; } # ${^POSTMATCH} and ${^PREMATCH} are also available with the use of '/p' # Named capture groups can be called via $+{name}

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 Perl, please visit: http://perldoc.perl.org/perlre.html