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
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  • Quantifiers
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  • 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

/
/
xgJ

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 = "(?xJ)(?(DEFINE)" & @CRLF & _ "(?<add> \s*\+\s* )" & @CRLF & _ "(?<eq> \s*=\s* )" & @CRLF & _ "# Remove all zeroes except the last one if the number is 0" & @CRLF & _ "(?<zero> (?:0(?=\d))*+ )" & @CRLF & _ "# cl: last digit of left operand being 1, cr: last digit of right operand being 1, \d(?:0|\b) check if last digit from result is 0" & @CRLF & _ "# there will be carry if cl and cr are set, or cl or cr are set and the last digit from result is 0" & @CRLF & _ "(?<carry> (?(cl)(?(cr)|\d(?:0|\b))|(?(cr)\d(?:0|\b)|(*F))) )" & @CRLF & _ "# add carry with l1 (current digit of left operand being 1) and r1 (current digit of right operand being 1)" & @CRLF & _ "# i.e. returns result of carry + l1 + r1 in Z/2Z" & @CRLF & _ "(?<digitadd> (?(?= (?(?=(?(l1)(?(r1)|(*F))|(?(r1)(*F))))(?&carry)|(?!(?&carry))) )1|0) )" & @CRLF & _ "# check for a single digit at the current offset whether the result is correct" & @CRLF & _ "# ro: right operand out of bounds (i.e. the current digit is at a higher offset than the size of the left operand)" & @CRLF & _ "# if we're out of bounds of the right operand, cr is just not set (i.e. handled as if there were leading zeroes)" & @CRLF & _ "(?<recursedigit>" & @CRLF & _ "# now, with the r and f, we can figure out r1 and cr at the current offset and also perform binary carry addition at that offset in the result" & @CRLF & _ " (?&add) (?&zero) (?:\d*(?:0|1(?<r1>)))? (?(ro)|(?=(?<cr>1)?))\k<r> (?&eq) \d*(?&digitadd)\k<f>\b" & @CRLF & _ "# iterate through the whole left operand to find the sequences (for right operand and result) of the same length as the offset of the current digit" & @CRLF & _ "| (?=\d* (?&add) (?&zero) (?:\k<r>(?<ro>)|\d*(?<r>\d\k<r>)) (?&eq) \d*(?<f>\d\k<f>)\b) \d(?&recursedigit)" & @CRLF & _ ")" & @CRLF & _ "# run the check, sets l1 and cl accordingly and initializes the r (right operand) and f (final result) groups to be empty" & @CRLF & _ "(?<checkdigit> (?:0|1(?<l1>)) (?=(?<cl>1)?) (?<r>) (?<f>) (?&recursedigit) )" & @CRLF & _ "# "trivial" increment of a binary number, i.e. a +1 is applied to the part of the right operand which exceeds the length of the left operand" & @CRLF & _ "(?<carryoverflow>" & @CRLF & _ "# number contains a zero, just update the part after the last zero" & @CRLF & _ " (?<x>\d+) 0 (?<y> \k<r> (?&eq) 0*\k<x>1 | 1(?&y)0 )" & @CRLF & _ "# number contains only ones, add a leading 1 and replace all the ones by zeroes" & @CRLF & _ "| (?<z> 1\k<r> (?&eq) 0*10 | 1(?&z)0 )" & @CRLF & _ ")" & @CRLF & _ "# ensure correct lengths of the final operand and handle right operands being longer than the left operand" & @CRLF & _ "(?<recurseoverflow>" & @CRLF & _ "# the left operand is longer than or as long as the right one. In the latter case, the final result will always be exactly one digit longer than the operands" & @CRLF & _ "# in the former case, if the first non-leading zero (from the left) of the left operand is at a higher or equal offset to the length of the right operand, the final result will be one digit longer than the left operand" & @CRLF & _ " (?&add) 0*+ (?(rlast) \k<r> (?&eq) 0*(?(ro)(?(addone)1)|1)\k<f>\b" & @CRLF & _ "# the right operand has a zero at the offset equal to the length of the left operand. Then just copy the leading digits to the final result" & @CRLF & _ " | (?:(?<remaining>\d+)(?=0\d* (?&eq) \d*(?=1)\k<f>\b)\k<r> (?&eq) (*PRUNE) 0*\k<remaining>\k<f>\b" & @CRLF & _ "# otherwise there will be some carry which needs to be applied before copying the leading digits to the final result" & @CRLF & _ " | (?&carryoverflow)\k<f>\b))" & @CRLF & _ "# iterate through the whole left operand to find the sequences (for right operand and result) of the same length as the left operand" & @CRLF & _ "| (?=\d* (?&add) 0*+ (?:\k<r>(?<ro>)|(?=(?:\d\k<r>(?&eq)(?<rlast>))?)\d*(?<r>\d\k<r>)) (?&eq) \d*(?<f>\d\k<f>)\b)" & @CRLF & _ "# check - only at the first non-leading zero - whether the right operand is longer than the current offset of the iteration, or just as long and having a carry (i.e. the digit at that offset in the final result is 0)" & @CRLF & _ " (?(nullchecked)|(?=(?<addone>(?=0)(?=(?:\d(?=\d*(?&add)\d*(?&eq)\d*(?<c>\d\k<c>)\b))+(?&add))(?<longer>(?&add)0*|\d(?&longer)\d)(\d+(?&eq)|(?&eq)\d*(?=0)\k<c>))?)(?=(?<nullchecked>0)?))" & @CRLF & _ " \d(?&recurseoverflow)" & @CRLF & _ ")" & @CRLF & _ "(?<s>" & @CRLF & _ " (?=\d) 0*? (?<arg>[01]+)? (?&add) (?=\d) 0*? (?<arg>(?(arg)(*F))[01]+)? (?&eq) (*PRUNE) \k<arg>" & @CRLF & _ "| (?&zero)" & @CRLF & _ "# traverse the digits one by one and verify the correctness of each offset individually" & @CRLF & _ " (?=(?<iteratedigits> (?=(?&checkdigit))\d (?:\b|(?&iteratedigits)) ))" & @CRLF & _ "# assert exact format here" & @CRLF & _ " (?=[01]+ (?&add) [01]+ (?&eq) [01]+ \b)" & @CRLF & _ "# remove leading zeroes and force an additional digit on the final result in case the left operand is only ones and the right operand not longer than the left" & @CRLF & _ " 0*? (?<r>) (?<f>) (?<c>) (?=(?<addone>1+(?&add))?) (?&recurseoverflow)" & @CRLF & _ "# Handle 0 + x or x + 0 separately to avoid messing around in the big subpatterns" & @CRLF & _ ")" & @CRLF & _ ")" & @CRLF & _ "\b(?&s)\b" Local $sString = "- 1 + 1 = 0" & @CRLF & _ "- 1 + 1 = 1" & @CRLF & _ "- 0 + 1 = 11" & @CRLF & _ "+ 1 + 1 = 10" & @CRLF & _ "- 1 + 10 = 101" & @CRLF & _ "- 0 + 11 = 101" & @CRLF & _ "+ 0 + 1 = 1" & @CRLF & _ "- 0 + 0 = 10" & @CRLF & _ "+ 1 + 0 = 1" & @CRLF & _ "- 1 + 101 = 1010" & @CRLF & _ "+ 10 + 0 = 10" & @CRLF & _ "+ 10 + 1 = 11" & @CRLF & _ "+ 11 + 1 = 100" & @CRLF & _ "+ 100 + 1 = 101" & @CRLF & _ "+ 01 + 10 = 11" & @CRLF & _ "+ 10 + 10 = 100" & @CRLF & _ "+ 010 + 010 = 100" & @CRLF & _ "+ 101 + 11 = 1000" & @CRLF & _ "- 101 + 10 = 1111" & @CRLF & _ "- 100 + 10 = 111" & @CRLF & _ "- 101 + 10 = 101" & @CRLF & _ "+ 101 + 10 = 111" & @CRLF & _ "+ 11 + 101 = 1000" & @CRLF & _ "+ 11 + 1011 = 1110" & @CRLF & _ "+ 11 + 10101 = 11000" & @CRLF & _ "+ 1 + 1111 = 10000" & @CRLF & _ "+ 111 + 11 = 1010" & @CRLF & _ "+ 1110 + 100 = 10010" & @CRLF & _ "+ 11 + 11 = 110" & @CRLF & _ "+ 1111 + 11 = 10010" & @CRLF & _ "- 010 + 010 = 000" & @CRLF & _ "- 100 + 100 = 1100" & @CRLF & _ "+ 100 + 100 = 1000" & @CRLF & _ "+ 1000 + 100 = 1100" & @CRLF & _ "+ 1 + 1000 = 1001" & @CRLF & _ "+ 1000 + 1 = 1001" & @CRLF & _ "+ 110 + 1100 = 10010" & @CRLF & _ "- 110 + 1010 = 1000" & @CRLF & _ "- 10 + 1 = 11111001" 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