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

/
/
g

Test String

Code Generator

Generated Code

#include <StringConstants.au3> ; to declare the Constants of StringRegExp #include <Array.au3> ; UDF needed for _ArrayDisplay and _ArrayConcatenate Local $sRegex = "\(+\*+(?:(?:\(+\*+(?:(?:\(+\*+(?:[^*(]|(?:\*+[^)*])|(?:\(+[^*(]))*\*+\)+)|[^*(]|(?:\*+[^)*])|(?:\(+[^*(]))*\*+\)+)|[^*(]|(?:\*+[^)*])|(?:\(+[^*(]))*\*+\)+" Local $sString = "The following regex handles any (* *) style string. Let's call it p{1}" & @CRLF & _ "" & @CRLF & _ " p{1} = \(+\*+(?:[^*(]|(?:\*+[^)*])|(?:\(+[^*(]))*\*+\)+" & @CRLF & _ "" & @CRLF & _ "The targeted string can include the characters {*, (, )}, but not the character sequences "(*" or "*)" (on which the regex terminates)." & @CRLF & _ "" & @CRLF & _ "Examples:" & @CRLF & _ "" & @CRLF & _ " (* simple one *)" & @CRLF & _ " (* more * ) ( * () **( difficult * ))()*(( one *)" & @CRLF & _ " (* r *( e*a) () * * l ()* * ( ) ) l * ( ) ) * **( y bad *)" & @CRLF & _ "" & @CRLF & _ "Explanation:" & @CRLF & _ "" & @CRLF & _ " \(+\*+ # begin with a (* sequence (or some variation like ((* or ((**, etc.)" & @CRLF & _ " (?: # begin comment content" & @CRLF & _ " [^*(] # allow any non-* non-( characters (which begin open/close brackets)" & @CRLF & _ " | # also" & @CRLF & _ " (?:\*+[^)*]) # allow * 1+ times in a row ONLY if it's not immediately followed by ) or *" & @CRLF & _ " | # also" & @CRLF & _ " (?:\(+[^*(]) # allow ( 1+ times in a row ONLY if it's not immediately followed by * or (" & @CRLF & _ " )* # allow any number of these characters / character sequences" & @CRLF & _ " \*+\)+ # then close the comment with a *) (or some variation like **) or *))), etc.)" & @CRLF & _ "" & @CRLF & _ "To capture un-nested and nested comments, simply allow comments inside of comments. ie:" & @CRLF & _ "" & @CRLF & _ " p{2} = \(+\*+(?:(?:p{1})|[^*(]|(?:\*+[^)*])|(?:\(+[^*(]))*\*+\)+" & @CRLF & _ "" & @CRLF & _ "in other words" & @CRLF & _ "" & @CRLF & _ " p{2} = \(+\*+(?:(?:\(+\*+(?:[^*(]|(?:\*+[^)*])|(?:\(+[^*(]))*\*+\)+)|[^*(]|(?:\*+[^)*])|(?:\(+[^*(]))*\*+\)+" & @CRLF & _ "" & @CRLF & _ "You'll see that this works on the following examples:" & @CRLF & _ " (* test (* one *) *)" & @CRLF & _ " (* a bit * ( ) * harder (* ) * () (( *) *)" & @CRLF & _ " (* r *( (( e **( a ) ((* l *() l *) y * bad * ( *)" & @CRLF & _ "" & @CRLF & _ "To capture up to triply-nested comments, follow the pattern set by p{2}:" & @CRLF & _ "" & @CRLF & _ " p{3} = \(+\*+(?:(?:p{2})|[^*(]|(?:\*+[^)*])|(?:\(+[^*(]))*\*+\)+" & @CRLF & _ "" & @CRLF & _ " p{3} = \(+\*+(?:(?:\(+\*+(?:(?:\(+\*+(?:[^*(]|(?:\*+[^)*])|(?:\(+[^*(]))*\*+\)+)|[^*(]|(?:\*+[^)*])|(?:\(+[^*(]))*\*+\)+)|[^*(]|(?:\*+[^)*])|(?:\(+[^*(]))*\*+\)+" & @CRLF & _ "" & @CRLF & _ "Examples:" & @CRLF & _ " (* an (* easy (* one *) *) *)" & @CRLF & _ " (* only (* some (* levels (* captured *) because *) 4x *) nested *)" & @CRLF & _ "" & @CRLF & _ "The pattern can be followed to allow any depth of nested comments to be captured, by defining" & @CRLF & _ "" & @CRLF & _ " p{N} = \(+\*+(?:(?:p{N-1})|[^*(]|(?:\*+[^)*])|(?:\(+[^*(]))*\*+\)+" & @CRLF & _ "" & @CRLF & _ "for N > 1" & @CRLF & _ "" & @CRLF & _ "" Local $aArray = StringRegExp($sString, $sRegex, $STR_REGEXPARRAYGLOBALFULLMATCH) Local $aFullArray[0] For $i = 0 To UBound($aArray) -1 _ArrayConcatenate($aFullArray, $aArray[$i]) Next $aArray = $aFullArray ; Present the entire match result _ArrayDisplay($aArray, "Result")

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