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

/
/
g

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`<center>(.|\n)*?<\/center>`) var str = `</head> <body style="background-color:#9b9b9b;"> **<center> <table width="580" border="0" cellspacing="0" cellpadding="0" align="center" class ="responsive-table" style="background-color:#3e5b3e;border:solid thin #3e5b3e;" > <tbody> <tr> <td background="http://app.randomsite.com/js/ckfinder/userfiles//images/banner.jpg" style="padding-top:20px;padding-right:20px;padding-left:20px;" class="hideForMobile"><h1 style="font-family:Arial, Helvetica, sans-serif;font-size:20px;font-weight:bold;text-align:right;color:#eee;vertical-align:bottom;text-decoration:none;margin-top:0;margin-bottom:0;margin-right:0;margin-left:0;" >some message</h1></td> </tr> <tr> </center>** <!---Start of Banner Image---> <td><a href="{{Custom1}}" style="color:inherit;text-decoration:none;" ><img src="http://app.clientcommand.com/js/ckfinder/userfiles//images/top-dollar-ford-banner.jpg" alt="" class="table.responsiveImage" style="display:block;width:100%;border-style:none;" /></a></td> <!---End of Banner Image---> </tr> <tr> **<center> <table width="580" border="0" cellspacing="0" cellpadding="0" align="center" class ="responsive-table" style="background-color:#3e5b3e;border:solid thin #3e5b3e;" > <tbody> <tr> <td background="http://app.randomsite.com/js/ckfinder/userfiles//images/banner.jpg" style="padding-top:20px;padding-right:20px;padding-left:20px;" class="hideForMobile"><h1 style="font-family:Arial, Helvetica, sans-serif;font-size:20px;font-weight:bold;text-align:right;color:#eee;vertical-align:bottom;text-decoration:none;margin-top:0;margin-bottom:0;margin-right:0;margin-left:0;" >some message</h1></td> </tr> <tr> </center>**` for i, match := range re.FindAllString(str, -1) { fmt.Println(match, "found at index", i) } }

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 Golang, please visit: https://golang.org/pkg/regexp/