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山东队cba赛程 :_t_ʽ漆(regexlabƷ)

cba㶫 www.axwwg.com  •rg2020-02-26 19:42:59   ߣ   ҪuՓ(0)


t_ʽregular expressionһַһȻȥCһַǷ@ _ʽab+ ǡһ

t_ʽregular expressionһַһȻȥCһַǷ@ _ʽab+ ǡһ 'a' ₀ 'b' ô 'ab', 'abb', 'abbbbbbbbbb' @

t_ʽÁ1CַǷָCǷǺϷ]ַ2ÁַһLıвҷַָȲҹ̶ַ`3ÁQͨQ

t_ʽW䌍ǺܺεĎׂ^ĸҲ֮Ժܶ˸Xt_ʽ^sһęn]ɜ\vϛ]עȺoxߵ⎧yһNԎęnһ㶼ҪBеĹȻ@еĹܲ҂Ҫ

еÿһecM뵽yԇMМyԇeԒf_ʼ

1. t_ʽҎt

1.1 ַͨ

ĸh„Լ߅¹Л]ⶨxĘc̖"ַͨ"_ʽеַͨƥһַĕrƥc֮ͬһַ

e1_ʽ "c"ƥַ "abcde" rƥYǣɹƥ䵽ăǣ"c"ƥ䵽λǣ_ʼ2Y3ע˜ˏ0_ʼ߀Ǐ1_ʼǰZԵIJͬܲͬ

e2_ʽ "bcd"ƥַ "abcde" rƥYǣɹƥ䵽ăǣ"bcd"ƥ䵽λǣ_ʼ1Y4

1.2 εDxַ

һЩַǰ "\" ķ@Щַ䌍҂ѽ֪

ƥ
\r, \n ܇͓Qз
\t Ʊ
\\ "\"

߀һЩں߅¹̎Ęc̖ǰ "\" ʹԓ̖磺^, $ xҪƥַ "^" "$" ַt_ʽҪ "\^" "\$"

ƥ
\^ ƥ ^ ̖
\$ ƥ $ ̖
\. ƥСc.

@ЩDxַƥ䷽c "ַͨ" ƵҲƥc֮ͬһַ

e1_ʽ "\$d"ƥַ "abc$de" rƥYǣɹƥ䵽ăǣ"$d"ƥ䵽λǣ_ʼ3Y5

1.3 ܉c 'Nַ' ƥı_ʽ

t_ʽеһЩʾƥ 'Nַ' еһַ_ʽ "\d" ƥһmȻƥַֻһǶ@ͺñƕrСԴһֻܴһ

ƥ
\d һ0~9 еһ
\w һĸֻ„Ҳ A~Z,a~z,0~9,_ һ
\s ոƱQ퓷ȿհַһ
. Сcƥ˓Qз\nһַ

e1_ʽ "\d\d"ƥ "abc123" rƥĽYǣɹƥ䵽ăǣ"12"ƥ䵽λǣ_ʼ3Y5

e2_ʽ "a.\d"ƥ "aaa100" rƥĽYǣɹƥ䵽ăǣ"aa1"ƥ䵽λǣ_ʼ1Y4

1.4 Զx܉ƥ 'Nַ' ı_ʽ

ʹ÷̖ [ ] һϵַ܉ƥһַ [^ ] һϵַt܉ƥַ֮һַͬӵĵmȻƥһֻһǶ

ƥ
[[email protected]] ƥ "a" "b" "5" "@"
[^abc] ƥ "a","b","c" ֮һַ
[f-k] ƥ "f"~"k" ֮gһĸ
[^A-F0-3] ƥ "A"~"F","0"~"3" ֮һַ

e1_ʽ "[bcd][bcd]" ƥ "abc123" rƥĽYǣɹƥ䵽ăǣ"bc"ƥ䵽λǣ_ʼ1Y3

e2_ʽ "[^abc]" ƥ "abc123" rƥĽYǣɹƥ䵽ăǣ"1"ƥ䵽λǣ_ʼ3Y4

1.5 ƥΔ̖

ǰ¹vı_ʽoՓֻƥһNַı_ʽ߀ǿƥNַһı_ʽֻƥһʹñ_ʽټƥΔ̖ô؏͕_ʽͿ؏ƥ

ʹ÷ǣ"Δ""ı_ʽ"߅磺"[bcd][bcd]" Ԍ "[bcd]{2}"

{n} _ʽ؏n磺 "\w{2}" ஔ "\w\w" "a{5}" ஔ "aaaaa"
{m,n} _ʽ؏m؏n磺 "ba{1,3}"ƥ "ba""baa""baaa"
{m,} _ʽ؏m磺 "\w\d{2,}"ƥ "a12","_456","M12344"...
? ƥ_ʽ0λ1ஔ {0,1}磺 "a[cd]?"ƥ "a","ac","ad"
+ _ʽٳF1ஔ {1,}磺 "a+b"ƥ "ab","aab","aaab"...
* _ʽFFஔ {0,}磺 "\^*b"ƥ "b","^^^b"...

e1_ʽ "\d+\.?\d*" ƥ "It costs $12.5" rƥĽYǣɹƥ䵽ăǣ"12.5"ƥ䵽λǣ_ʼ10Y14

e2_ʽ "go{2,8}gle" ƥ "Ads by goooooogle" rƥĽYǣɹƥ䵽ăǣ"goooooogle"ƥ䵽λǣ_ʼ7Y17

1.6 һЩx̖

һЩ̖ڱ_ʽдx

^ cַ_ʼĵطƥƥκַ
$ cַYĵطƥƥκַ
\b ƥһ~߅Ҳdž~Ϳո֮gλƥκַ

MһfȻ^e

e1_ʽ "^aaa" ƥ "xxx aaa xxx" rƥYǣʧ "^" Ҫcַ_ʼĵطƥֻЮ "aaa" λַ_^ĕr"^aaa" ƥ 磺"aaa xxx xxx"

e2_ʽ "aaa$" ƥ "xxx aaa xxx" rƥYǣʧ "$" ҪcַYĵطƥֻЮ "aaa" λַĽYβĕr"aaa$" ƥ 磺"xxx xxx aaa"

e3_ʽ ".\b." ƥ "@@@abc" rƥYǣɹƥ䵽ăǣ"@a"ƥ䵽λǣ_ʼ2Y4
Mһf"\b" c "^" "$" ƥκַҪƥY̎λõ҃߅һ߅ "\w" һ߅ "\w" ķ

e4_ʽ "\bend\b" ƥ "weekend,endfor,end" rƥYǣɹƥ䵽ăǣ"end"ƥ䵽λǣ_ʼ15Y18

һЩ̖Ӱ푱_ʽȲӱ_ʽ֮gPϵ

| ҃߅_ʽ֮g "" Pϵƥ߅߅
( ) (1). ڱƥΔĕr̖еı_ʽw
(2). ȡƥYĕr̖еı_ʽƥ䵽ăݿԱΪõ

e5_ʽ "Tom|Jack" ƥַ "I'm Tom, he is Jack" rƥYǣɹƥ䵽ăǣ"Tom"ƥ䵽λǣ_ʼ4Y7ƥһrƥYǣɹƥ䵽ăǣ"Jack"ƥ䵽λÕr_ʼ15Y19

e6_ʽ "(go\s*)+" ƥ "Let's go go go!" rƥYǣɹƥ䵽ǣ"go go go"ƥ䵽λǣ_ʼ6Y14

e7_ʽ "(\d+\.?\d*)" ƥ "10.9,20.5" rƥĽYǣɹƥ䵽ăǣ"20.5"ƥ䵽λǣ_ʼ6Y10Ϊ@ȡ̖ƥ䵽ăǣ"20.5"

2. t_ʽеһЩ߼Ҏt

2.1 ƥΔе؝c؝

ʹƥΔ̖rЎ׷Nʾʹͬһ_ʽ܉ƥ䲻ͬĴΔ磺"{m,n}", "{m,}", "?", "*", "+"wƥĴΔSƥַ@N؏ƥ䲻Δı_ʽƥ^DZMܶƥᘌı "dxxxdxxxd"e£

ƥY
(d)(\w+) "\w+" ƥһ "d" ַ֮ "xxxdxxxd"
(d)(\w+)(d) "\w+" ƥһ "d" һ "d" ֮gַ "xxxdxxx"mȻ "\w+" Ҳ܉ƥһ "d"Ǟʹ_ʽƥɹ"\w+" "׌" ܉ƥһ "d"

ɴ˿Ҋ"\w+" ƥĕrDZMܶƥҎtַmȻڶe]ƥһ "d"ҲǞ׌_ʽ܉ƥɹͬ "*" "{m,n}" ı_ʽDZMܵضƥ "?" ı_ʽڿƥɲƥĕrҲDZMܵ "Ҫƥ"@ Nƥԭtͽ "؝" ģʽ 

؝ģʽ

ƥΔ̖ټһ "?" ̖tʹƥΔı_ʽMٵƥʹƥɲƥı_ʽMܵ "ƥ"@Nƥԭt "؝" ģʽҲ "㏊" ģʽƥ͕_ʽƥʧĕrc؝ģʽ؝ģʽС޶ȵƥһЩʹ_ʽƥɹeᘌı "dxxxdxxxd" e

ƥY
(d)(\w+?) "\w+?" Mٵƥһ "d" ַ֮Yǣ"\w+?" ֻƥһ "x"
(d)(\w+?)(d) ׌_ʽƥɹ"\w+?" òƥ "xxx" ſ׌߅ "d" ƥĶʹ_ʽƥɹYǣ"\w+?" ƥ "xxx"

re£

e1_ʽ "<td>(.*)</td>" cַ "<td><p>aa</p></td> <td><p>bb</p></td>" ƥrƥĽYǣɹƥ䵽ă "<td><p>aa</p></td> <td><p>bb</p></td>" ַ _ʽе "</td>" cַһ "</td>" ƥ

e2֮_ʽ "<td>(.*?)</td>" ƥe1ͬӵַrֻõ "<td><p>aa</p></td>" ٴƥһrԵõڶ "<td><p>bb</p></td>"

2.2 \1, \2...

_ʽƥr_ʽС̖ "( )" ı_ʽƥ䵽ַӛګ@ȡƥYĕrС̖ı_ʽƥ䵽ַԆΪ@ȡ@һcǰeѽչʾڌHÈijN߅Ҫ@ȡăֲ߅rʹСָ̖Ҫķǰ "<td>(.*?)</td>"

䌍"С̖ı_ʽƥ䵽ַ" HƥYſʹƥ^Ҳʹ_ʽ߅IJǰ "̖ȵƥѽƥ䵽ַ"÷ "\" һ"\1" õ1̖ƥ䵽ַ"\2" õ2̖ƥ䵽ַԴһ̖Ȱһ̖tӵ̖̖?仰?һ̖ "(" ǰ@һ̖



e1_ʽ "('|")(.*?)(\1)" ƥ " 'Hello', "World" " rƥYǣɹƥ䵽ăǣ" 'Hello' "ٴƥһrƥ䵽 " "World" "

e2_ʽ "(\w)\1{4,}" ƥ "aa bbbb abcdefg ccccc 111121111 999999999" rƥYǣɹƥ䵽ă "ccccc"ٴƥһrõ 999999999@_ʽҪ "\w" ַ؏5 עc "\w{5,}" ֮gą^e

e3_ʽ "<(\w+)\s*(\w+(=('|").*?\4)?\s*)*>.*?</\1>" ƥ "<td id='td1' style="bgcolor:white"></td>" rƥYdzɹ "<td>" c "</td>" 䌦tƥʧij䌦Ҳƥɹ

2.3 AƥAƥ

ǰ¹vˎׂx̖"^""$""\b"һͬcǾǣƥκַֻnj "ַă^" "ַ֮gĿp϶" һl⵽@Ժ^mBһN "^" "p϶" ӗl`ıʾ

A"(?=xxxxx)""(?!xxxxx)"

ʽ"(?=xxxxx)"ڱƥַ̎ "p϶" "^" ӵėlǣڿp϶҂܉ƥ xxxxx @ֵı_ʽֻڴ@p϶ϸӵėlӰ푺߅ı_ʽȥƥ@p϶ַ֮@ "\b"ƥκַ"\b" ֻnjڿp϶֮ǰַ֮ȡMһДӰ푺߅ı_ʽƥ

e1_ʽ "Windows (?=NT|XP)" ƥ "Windows 98, Windows NT, Windows 2000" rֻƥ "Windows NT" е "Windows " "Windows " ֘ӄtƥ

e2_ʽ "(\w)((?=\1\1\1)(\1))+" ƥַ "aaa ffffff 999999999" rƥ6"f"ǰ4ƥ9"9"ǰ7@_ʽxɣ؏4ϵĸtƥʣ2λ֮ǰIJȻ@_ʽԲ@ӌڴ˵Ŀʾ֮

ʽ"(?!xxxxx)"ڿp϶҂횲ƥ xxxxx @ֱ_ʽ

e3_ʽ "((?!\bstop\b).)+" ƥ "fdjka ljfdl stop fjdsla fdj" r^һֱƥ䵽 "stop" ֮ǰλַЛ] "stop"tƥַ

e4_ʽ "do(?!\w)" ƥַ "done, do, dog" rֻƥ "do"ڱle"do" ߅ʹ "(?!\w)" ʹ "\b" Чһӵ

A"(?<=xxxxx)""(?<!xxxxx)"

@ɷNʽĸAƵAҪėlǣڿp϶ ""ɷNʽքeҪ܉ƥͱ횲܉ƥָ_ʽȥД҂c "A" һӵǣnjڿp϶һNӗlƥκַ

e5_ʽ "(?<=\d{4})\d+(?=\d{4})" ƥ "1234567890123456" rƥǰ4ֺͺ4֮g8 JScript.RegExp ַ֧Ale܉Mʾַ֧ܶA磺Java 1.4 ϵ java.util.regex .NET System.Text.RegularExpressions gԼվ]õ DEELX t

3. ͨҎt

߀һЩڸt_ʽ֮g^ͨõҎtǰv^Л]ᵽ

3.1 _ʽʹ "\xXX" "\uXXXX" ʾһַ"X" ʾһʮMƔ

ʽ

ַ
\xXX ̖ 0 ~ 255 ַ磺 ոʹ "\x20" ʾ
\uXXXX κַʹ "\u" ټ侎̖4λʮMƔʾ磺 "\u4E2D"

3.2 ڱ_ʽ "\s""\d""\w""\b" ʾxͬrĴĸʾ෴x

ƥ
\S ƥзǿհַ"\s" ƥհַ
\D ƥеķǔַ
\W ƥеĸ„ַ
\B ƥdž~߅҃߅ "\w" ҃߅ "\w" rַp϶

3.3 ڱ_ʽxҪ "\" ƥԓַַR

ַ

f
^ ƥݔַ_ʼλҪƥ "^" ַՈʹ "\^"
$ ƥݔַĽYβλҪƥ "$" ַՈʹ "\$"
( ) ӛһӱ_ʽ_ʼͽYλҪƥС̖Ոʹ "\(" "\)"
[ ] ÁԶx܉ƥ 'Nַ' ı_ʽҪƥ̖Ոʹ "\[" "\]"
{ } ƥΔķ̖Ҫƥ̖Ոʹ "\{" "\}"
. ƥ˓Qз\nһַҪƥСcՈʹ "\."
? ƥΔ 0 λ 1 Ҫƥ "?" ַՈʹ "\?"
+ ƥΔ 1 Ҫƥ "+" ַՈʹ "\+"
* ƥΔ 0 λҪƥ "*" ַՈʹ "\*"
| ҃߅_ʽ֮g "" Pϵƥ "|" Ոʹ "\|"

3.4 ̖ "( )" ȵӱ_ʽϣƥYMӛ䛹Ժʹʹ "(?:xxxxx)" ʽ

e1_ʽ "(?:(\w)\1)+" ƥ "a bbccdd efg" rY "bbccdd"̖ "(?:)" ƥYMӛ "(\w)" ʹ "\1" 

3.5 õı_ʽOú飺IgnorecaseSinglelineMultilineGlobal

f
Ignorecase ĬJr_ʽеĸҪ^ִСÞ Ignorecase ʹƥr^ִСеı_ʽ "С" UNICODE ĴС
Singleline ĬJrСc "." ƥ˓Qз\nַÞ Singleline ʹСcƥQзڃȵַ
Multiline ĬJr_ʽ "^" "$" ֻƥַ_ʼ ͽYβ λ磺

xxxxxxxxx\n
xxxxxxxxx

Þ Multiline ʹ "^" ƥ ߀ƥQз֮һ_ʼǰ λʹ "$" ƥ ߀ƥQз֮ǰһнY λ
Global Ҫڌ_ʽÁQrÞ Global ʾQеƥ

4. ʾ

4.1 Ҫ˽߼t߀֧ЩstZɅҊվ DEELX tfęn

4.2 ҪҪ_ʽƥăַǏַһôڱ_ʽβʹ "^" "$"磺"^\d+$" ҪַֻД

4.3 ҪƥăһĆ~dž~һôڱ_ʽβʹ "\b"磺 ʹ "\b(if|while|else|void|int)\b" ƥеPI

4.4 _ʽҪƥַtһֱõƥɹYʲô]ƥ䵽磺ʂ䌑һƥ "123""123.""123.5"".5" @׷Nʽı_ʽrСcСֶʡDzҪ_ʽɣ"\d*\.?\d*"ʲô]@_ʽҲƥɹ õČǣ"\d+\.?\d*|\.\d+"

4.5 ƥַƥ䲻Ҫѭho޴̖ȵӱ_ʽеÿһֶƥ 0 @̖wֿƥo޴ôrܱһlfĸƥ^пѭhmȻFЩt_ʽѽͨ^k@NrFѭh .NET t_ʽ҂ȻԓMF@Nr҂ڌ_ʽrѭhҲԏ@һcһǷDZlfԭ

4.6 x؝ģʽc؝ģʽҊԒ}ӑՓ

4.7 "|" ҃߅ijַֻһ߅ƥ@ "|" ߅ı_ʽ齻Qλöͬ

5. MAc

5.1 Ҫʾ t Regex Match Tracer 2.1 MѿMoʹã

Ҳ]ҿһ

t_ʽ30T̳

JavaScriptt_ʽھyԇ

@ƪPڽ_t_ʽ漆(regexlabƷ)¾ͽB@,Pt_ʽ漆Ո_֮ǰ»^mg[PϣԺ֧_֮

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