Regular expression

REGULAR EXPRESSIONLarry Nung

AGENDASyntaxExampleReferenceQ & A

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SYNTAX3

SPECIAL CHARACTERS

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Metacharacter

Description

* Zero or more+ One or more? Zero or one; Not greedy^ Beginning of string$ End of string. Any[] Group{} Marks the start and end of a quantifier

expression() Capture| or\ Escape

METACHARACTERS

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Metacharacter

Description

\b Word boundary\B Non word boundary\d Decimal digit

Equivalent to [0-9]\D Non decimal digit

Equivalent to [^0-9]\w Word

Equivalent to [a-zA-Z_0-9]\W Non word

Equivalent to [^a-zA-Z_0-9][xyz] Group[^xyz] Negated group[a-z] Group

METACHARACTERS

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Metacharacter Description[^a-z] Negated group{n} Exactly N{n,} At least N{n,m} From N to M(pattern) Capture(?<name>pattern)

Named capture

(?:pattern) Non capture(?=pattern) Positive lookahead(?!pattern) Negative lookahead(?<=pattern) Positive lookbehind(?<!pattern) Negative lookbehind\cx CTRL char\xn ASCII value

NONPRINTING CHARACTERS

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Metacharacter

Description

\f Form feedEquivalent to \x0c\cL

\n New lineEquivalent to \x0a\cJ

\r Carriage returnEquivalent to \x0d\cM

\s Whitespace Equivalent to [\f\n\r\t\v]

\S Non whitespaceEquivalent to [^\f\n\r\t\v]

\t TabEquivalent to \x09\cI

\v Vertical tabEquivalent to \x0b\cK

ORDER OF PRECEDENCE

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Operator or operators

Description

\ Escape(), (?:), (?=), [] Parentheses and brackets*, +, ?, {n}, {n,}, {n,m}

Quantifiers

^, $, \anymetacharacter

Anchors and sequences

| Alternation

EXAMPLE9

EXAMPLE Digits

^[0-9]*$

Alphabetic characters ^[a-zA-Z]*$

Alpha-Numeric characters ^[a-zA-Z0-9]*$

Special characters [\W_]+ 10

EXAMPLE Lowercase alphabetic characters

^([a-z])*$

Uppercase alphabetic characters ^([A-Z])*$

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EXAMPLE Email

^([a-zA-Z0-9._%-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4})*$

IP ^(?:(?:25[0-5]|2[0-4]\d|[01]\d\d|\d?\d)(?(?=\.?\

d)\.)){4}$

Url ^(((http|https|ftp):\/\/)?([[a-zA-Z0-9]\-\.])+(\.)([[a-

zA-Z0-9]]){2,4}([[a-zA-Z0-9]\/+=%&_\.~?\-]*))*$12

EXAMPLE Date (MM/DD/YYYY)

^((0?[1-9]|1[012])[- /.](0?[1-9]|[12][0-9]|3[01])[- /.](19|20)?[0-9]{2})*$

Date (YYYY/MM/DD) ^((19|20)?[0-9]{2}[- /.](0?[1-9]|1[012])[- /.](0?[1-

9]|[12][0-9]|3[01]))*$

Time ([0-1][0-9]|2[0-3])\:[0-5][0-9]\:[0-5][0-9]

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EXAMPLE Tel

[0-9]{2}\-[0-9]{7}

Mobile [0-9]{4}\-[0-9]{3}\-[0-9]{3}

ID No ([A-Z]|[a-z])\d{9}

HTML element ^<([a-z]+)([^<]+)*(?:>(.*)<\/\1>|\s+\/>)$ 14

EXAMPLE Strong password

^(?=^.{6,}$)((?=.*[A-Za-z0-9])(?=.*[A-Z])(?=.*[a-z]))^.*$

Credit card ^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|

6011[0-9]{12}|622((12[6-9]|1[3-9][0-9])|([2-8][0-9][0-9])|(9(([0-1][0-9])|(2[0-5]))))[0-9]{10}|64[4-9][0-9]{13}|65[0-9]{14}|3(?:0[0-5]|[68][0-9])[0-9]{11}|3[47][0-9]{13})*$

MasterCard credit card ^(5[1-5][0-9]{14})*$

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EXAMPLE Zip code

^([0-9]{5}(?:-[0-9]{4})?)*$

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REFERENCE17

REFERENCE 正規表示式 - 維基百科，自由的百科全書

https://zh.wikipedia.org/wiki/%E6%AD%A3%E5%88%99%E8%A1%A8%E8%BE%BE%E5%BC%8F

正則表達式 30 分鐘入門教程 http://deerchao.net/tutorials/regex/regex.htm

正規化表示法 - ProgWiki http://www.player.idv.tw/prog/index.php/%

E6%AD%A3%E8%A6%8F%E5%8C%96%E8%A1%A8%E7%A4%BA%E6%B3%95 18

REFERENCE 正則表達式語法

https://msdn.microsoft.com/zh-cn/library/ae5bf541(v=vs.100).aspx

Regular Expression Library http://www.regexlib.com/?

AspxAutoDetectCookieSupport=1

Regular expression 常用驗證 | 程式設計筆記 http://

readily-notes.blogspot.tw/2010/09/regex.html 19

REFERENCE 37 Tested PHP, Perl, and JavaScript Regular

Expressions http://

www.virtuosimedia.com/dev/php/37-tested-php-perl-and-javascript-regular-expressions

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Q&A21

QUESTION & ANSWER

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