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 single character of: a, b, c or d
    [[ab][cd]]
  • 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]
  • Character class intersection
    [\w&&[^\d]]
  • 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

Substitution

Processing...

Code Generator

Generated Code

#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox Local $sRegex = "(?=(?:....)*$)" Local $sString = "<html>" & @CRLF & _ "<head>" & @CRLF & _ "<title>Credit Card Test</title>" & @CRLF & _ "</head>" & @CRLF & _ "" & @CRLF & _ "<body>" & @CRLF & _ "<h1>Credit Card Test</h1>" & @CRLF & _ "" & @CRLF & _ "<form>" & @CRLF & _ "<p>Please enter your credit card number:</p>" & @CRLF & _ "" & @CRLF & _ "<p><input type="text" size="20" name="cardnumber"" & @CRLF & _ " onkeyup="validatecardnumber(this.value)"></p>" & @CRLF & _ "" & @CRLF & _ "<p id="notice">(no card number entered)</p>" & @CRLF & _ "</form>" & @CRLF & _ "" & @CRLF & _ "<script>" & @CRLF & _ "function validatecardnumber(cardnumber) {" & @CRLF & _ " // Strip spaces and dashes" & @CRLF & _ " cardnumber = cardnumber.replace(/[ -]/g, '');" & @CRLF & _ " // See if the card is valid" & @CRLF & _ " // The regex will capture the number in one of the capturing groups" & @CRLF & _ " var match = /^(?:(4[0-9]{12}(?:[0-9]{3})?)|(5[1-5][0-9]{14})|↵" & @CRLF & _ "(6(?:011|5[0-9]{2})[0-9]{12})|(3[47][0-9]{13})|(3(?:0[0-5]|[68][0-9])↵" & @CRLF & _ "[0-9]{11})|((?:2131|1800|35[0-9]{3})[0-9]{11}))$/.exec(cardnumber);" & @CRLF & _ " if (match) {" & @CRLF & _ " // List of card types, in the same order as the regex capturing groups" & @CRLF & _ " var types = ['Visa', 'MasterCard', 'Discover', 'American Express'," & @CRLF & _ " 'Diners Club', 'JCB'];" & @CRLF & _ " // Find the capturing group that matched" & @CRLF & _ " // Skip the zeroth element of the match array (the overall match)" & @CRLF & _ " for (var i = 1; i < match.length; i++) {" & @CRLF & _ " if (match[i]) {" & @CRLF & _ " // Display the card type for that group" & @CRLF & _ " document.getElementById('notice').innerHTML = types[i - 1];" & @CRLF & _ " break;" & @CRLF & _ " }" & @CRLF & _ " }" & @CRLF & _ " } else {" & @CRLF & _ " document.getElementById('notice').innerHTML = '(invalid card number)';" & @CRLF & _ " }" & @CRLF & _ "}" & @CRLF & _ "</script>" & @CRLF & _ "</body>" & @CRLF & _ "</html>" & @CRLF & _ "" Local $sSubst = "-" Local $sResult = StringRegExpReplace($sString, $sRegex, $sSubst) MsgBox($MB_SYSTEMMODAL, "Result", $sResult)

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 AutoIt, please visit: https://www.autoitscript.com/autoit3/docs/functions/StringRegExp.htm