Regular Expressions

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Regular Expressions

Detection type	regular expression (math.)	Example of detection
train number	/^[GCDZTSPKXLY1-9]\d{1,4}$/	G1868、D102、D9、Z5、Z24、Z17
Cell Phone Body Code (IMEI)	/^\d{15,17}$/	123456789012345、1234567890123456
URL (or ip) with port number is required	/^((ht\|f)tps?:\/\/)?[\w-]+(\.[\w-]+)+:\d{1,5}\/?$/	127.0.0.1:5050、baidu.com:8001、https://www.udtool.com:80、http://192.168.1.1:9090
Web address (URL)	/^(((ht\|f)tps?):\/\/)?([^!@#$%^&?.\s-]([^!@#$%^&?.\s]{0,63}[^!@#$%^&*?.\s])?\.)+[a-z]{2,6}\/?/	https://xxx.org/v2/api/#v、www.udtool.com、www.qq.99、//www.udtool.com、ftp://baidu.qq、http://baidu.com、https://www.amap.com/search?id=BV1006、360.com:8080/vue/#/a=1
Unified Social Credit Code (USCC)	/^[0-9A-HJ-NPQRTUWXY]{2}\d{6}[0-9A-HJ-NPQRTUWXY]{10}$/	91230184MA1BUFLT44、92371000MA3MXH0E3W
Unified Social Credit Code (loose match) (15 digits/18 digits/20 digits/letters)	/^(([0-9A-Za-z]{15})\|([0-9A-Za-z]{18})\|([0-9A-Za-z]{20}))$/	91110108772551611J、911101085923662400
thunderbolt link	/^thunderx?:\/\/[a-zA-Z\d]+=$/	thunder://QUEsICdtYWduZXQ6P3h0PXVybjpidGloOjBCQTE0=
ed2k link (loose match)	/^ed2k:\/\/\\|file\\|.+\\|\/$/	ed2k://\|file\|%E5%AF%84%E7AB.PARASITE.2019.HD-1080p.X264.AAC-UUMp4(E00.COM).mp4\|2501554832\|C0BCBED732C20CE577A3\|h=5HTKZPQF\|/
Magnetic link (loose match)	/^magnet:\?xt=urn:btih:[0-9a-fA-F]{40,}.*$/	magnet:?xt=urn:btih:40A89A6F4FB1498A98087109D012A9A851FBE0FC
Subnet mask (without 0.0.0.0)	/^(254\|252\|248\|240\|224\|192\|128)\.0\.0\.0\|255\.(254\|252\|248\|240\|224\|192\|128\|0)\.0\.0\|255\.255\.(254\|252\|248\|240\|224\|192\|128\|0)\.0\|255\.255\.255\.(255\|254\|252\|248\|240\|224\|192\|128\|0)$/	255.255.255.0、255.255.255.255、255.240.0.0
linux "hidden file" paths	/^\/(?:[^/]+\/)\.[^/]/	/usr/ad/.dd、/root/.gitignore、/.gitignore
linux folder path	/^\/(?:[^/]+\/)*$/	/usr/ad/dd/、/、/root/、/aa/a/aa/
linux file path	/^\/(?:[^/]+\/)*[^/]+$/	/root/b.ts、/root/abc
Window "Folder" Path	/^[a-zA-Z]:\\(?:\w+\\?)*$/	C:\Users\Adminr\Desktop、e:\m\
Path to "file" under window	/^[a-zA-Z]:\$?:\w+\$*\w+\.\w+$/	C:\Users\Admin\Desktop\qq.link、e:\m\vscode.exe
Stock code (A shares)	/^(s[hz]\|S[HZ])(000[\d]{3}\|002[\d]{3}\|300[\d]{3}\|600[\d]{3}\|60[\d]{4})$/	sz000858、SZ002136、sz300675、SH600600、sh601155
Greater than or equal to 0, less than or equal to 150, support decimal places appearing 5, such as 145.5, used to determine the score of the examination paper	/^150$\|^(?:\d\|[1-9]\d\|1[0-4]\d)(?:\.5)?$/	150、100.5
html comments	/<!--[\s\S]*?-->/g	<!--<div class="_bubble"></div>--><div>chenguzhen87</div><div class="_bubble"></div>-->
md5 format (32-bit)	/^[a-fA-F0-9]{32}$/	21fe181c5bfc16306a6828c1f7b762e8
GUID/UUID	/^[a-f\d]{4}(?:[a-f\d]{4}-){4}[a-f\d]{12}$/i	e155518c-ca1b-443c-9be9-fe90fdab7345、41E3DAF5-6E37-4BCC-9F8E-0D9521E2AA8D
The version number must be in X.Y.Z format.	/^\d+(?:\.\d+){2}$/	16.3.10
Video link address (video format can be added or deleted as needed)	/^https?:\/\/(.+\/)+.+(\.(swf\|avi\|flv\|mpg\|rm\|mov\|wav\|asf\|3gp\|mkv\|rmvb\|mp4))$/i	http://www.udtool.com/video/wc.avi
Image link address (image format can be added or deleted as needed)	/^https?:\/\/(.+\/)+.+(\.(gif\|png\|jpg\|jpeg\|webp\|svg\|psd\|bmp\|tif))$/i	http://www.udtool.com/logo.png
24-hour time (HH:mm:ss)	/^(?:[01]\d\|2[0-3]):[0-5]\d:[0-5]\d$/	23:34:55
12-hour time (hh:mm:ss)	/^(?:1[0-2]\|0?[1-9]):[0-5]\d:[0-5]\d$/	11:34:55
base64 format	/^\sdata:(?:[a-z]+\/[a-z0-9-+.]+(?:;[a-z-]+=[a-z0-9-]+)?)?(?:;base64)?,([a-z0-9!$&',()+;=\-._~:@/?%\s]?)\s$/i	data:image/gif;base64,xxxx==
Numeric/currency amounts (support for negative numbers, thousands separators)	/^-?\d{1,3}(,\d{3})*(\.\d{1,2})?$/	100、-0.99、3、234.32、-1、900、235.09、12,345,678.90
ATM card number	/^[1-9]\d{9,29}$/	6234567890、6222026006705354000
Chinese Name	/^(?:[\u4e00-\u9fa5·]{2,16})$/	Ge, Kevin Durant, and Dirk Werner-Nowitzki.
Name in English	/(^[a-zA-Z][a-zA-Z\s]{0,20}[a-zA-Z]$)/	James、Kevin Wayne Durant、Dirk Nowitzki
License plate number (new energy)	/^[京津沪渝冀豫云辽黑湘皖鲁新苏浙赣鄂桂甘晋蒙陕吉闽贵粤青藏川宁琼使领][A-HJ-NP-Z](?:((\d{5}[A-HJK])\|([A-HJK][A-HJ-NP-Z0-9][0-9]{4}))\|[A-HJ-NP-Z0-9]{4}[A-HJ-NP-Z0-9挂学警港澳])$/	Beijing AD92035, Gan G23459F, Beijing AA92035
License plate number (non-new energy)	/^[京津沪渝冀豫云辽黑湘皖鲁新苏浙赣鄂桂甘晋蒙陕吉闽贵粤青藏川宁琼使领][A-HJ-NP-Z][A-HJ-NP-Z0-9]{4}[A-HJ-NP-Z0-9挂学警港澳]$/	Beijing A00599, Black D23908
License plate number (new energy + non-new energy)	/^[京津沪渝冀豫云辽黑湘皖鲁新苏浙赣鄂桂甘晋蒙陕吉闽贵粤青藏川宁琼使领][A-HJ-NP-Z][A-HJ-NP-Z0-9]{4,5}[A-HJ-NP-Z0-9挂学警港澳]$/	京A12345D、京A00599、京AD92035、甘G23459F、京AA92035
手机号(mobile phone)中国(严谨), 根据工信部2019最新公布的手机号段	/^(?:(?:\+\|00)86)?1(?:(?:3[\d])\|(?:4[5-79])\|(?:5[0-35-9])\|(?:6[5-7])\|(?:7[0-8])\|(?:8[\d])\|(?:9[1589]))\d{8}$/	008618311006933、+8617888829981、19119255642、19519255642
手机号(mobile phone)中国(宽松), 只要是13,14,15,16,17,18,19开头即可	/^(?:(?:\+\|00)86)?1[3-9]\d{9}$/	008618311006933、+8617888829981、19119255642
手机号(mobile phone)中国(最宽松), 只要是1开头即可, 如果你的手机号是用来接收短信, 优先建议选择这一条	/^(?:(?:\+\|00)86)?1\d{10}$/	008618311006933、+8617888829981、19119255642
Date (loose)	/^\d{1,4}(-)(1[0-2]\|0?[1-9])\1(0?[1-9]\|[1-2]\d\|30\|31)$/	1990-12-12、1-1-1、0000-1-1
Date (rigorous, supports leap year judgment)	/^(([0-9]{3}[1-9]\|[0-9]{2}[1-9][0-9]{1}\|[0-9]{1}[1-9][0-9]{2}\|[1-9][0-9]{3})-(((0[13578]\|1[02])-(0[1-9]\|[12][0-9]\|3[01]))\|((0[469]\|11)-(0[1-9]\|[12][0-9]\|30))\|(02-(0[1-9]\|[1][0-9]\|2[0-8]))))\|((([0-9]{2})(0[48]\|[2468][048]\|[13579][26])\|((0[48]\|[2468][048]\|[3579][26])00))-02-29)$/	1990-12-12、2000-02-29
Chinese province	/^浙江\|上海\|北京\|天津\|重庆\|黑龙江\|吉林\|辽宁\|内蒙古\|河北\|新疆\|甘肃\|青海\|陕西\|宁夏\|河南\|山东\|山西\|安徽\|湖北\|湖南\|江苏\|四川\|贵州\|云南\|广西\|西藏\|江西\|广东\|福建\|台湾\|海南\|香港\|澳门$/	Zhejiang, Taiwan
The time that can be successfully transformed by momentum YYYYMMDD HH:mm:ss	/^\d{4}([/:-\S])(1[0-2]\|0?[1-9])\1(0?[1-9]\|[1-2]\d\|30\|31) (?:[01]\d\|2[0-3]):[0-5]\d:[0-5]\d$/	2020/01/01 23:59:59、2020-01-01 00:00:00、20200101 11:11:11
email	/^(([^<>()[\]\\.,;:\s@"]+(\.[^<> ()[\]\\.,;:\s@"]+)*)\|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])\|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/	90203918@qq.com, nbilly@126.com, 汉字@qq.com
Tel phone (domestic), e.g. 0341-86091234	/^(?:(?:\d{3}-)?\d{8}\|^(?:\d{4}-)?\d{7,8})(?:-\d+)?$/	0936-4211235、89076543、010-12345678-1234
Identity card number (1 generation, 15 digits)	/^[1-9]\d{7}(?:0\d\|10\|11\|12)(?:0[1-9]\|[1-2][\d]\|30\|31)\d{3}$/	123456991010193
Identity card number (2 generations, 18 digits), the last digit is a check digit, may be a number or character X	/^[1-9]\d{5}(?:18\|19\|20)\d{2}(?:0[1-9]\|10\|11\|12)(?:0[1-9]\|[1-2]\d\|30\|31)\d{3}[\dXx]$/	12345619991205131x
ID number, support 1/2 generation (15/18 digits)	/^\d{6}((((((19\|20)\d{2})(0[13-9]\|1[012])(0[1-9]\|[12]\d\|30))\|(((19\|20)\d{2})(0[13578]\|1[02])31)\|((19\|20)\d{2})02(0[1-9]\|1\d\|2[0-8])\|((((19\|20)([13579][26]\|[2468][048]\|0[48]))\|(2000))0229))\d{3})\|((((\d{2})(0[13-9]\|1[012])(0[1-9]\|[12]\d\|30))\|((\d{2})(0[13578]\|1[02])31)\|((\d{2})02(0[1-9]\|1\d\|2[0-8]))\|(([13579][26]\|[2468][048]\|0[048])0229))\d{2}))(\d\|X\|x)$/	622223199912051311、12345619991205131x、123456991010193
Passport (including Hong Kong and Macau)	/(^[EeKkGgDdSsPpHh]\d{8}$)\|(^(([Ee][a-fA-F])\|([DdSsPp][Ee])\|([Kk][Jj])\|([Mm][Aa])\|(1[45]))\d{7}$)/	s28233515、141234567、159203084、MA1234567、K25345719
Whether the account number is legal (starts with a letter, allows 5-16 bytes, allows alphanumeric underscore combinations)	/^[a-zA-Z]\w{4,15}$/	justin、justin1989、justin_666
Chinese/Handwriting	/^(?:[\u3400-\u4DB5\u4E00-\u9FEA\uFA0E\uFA0F\uFA11\uFA13\uFA14\uFA1F\uFA21\uFA23\uFA24\uFA27-\uFA29]\|[\uD840-\uD868\uD86A-\uD86C\uD86F-\uD872\uD874-\uD879][\uDC00-\uDFFF]\|\uD869[\uDC00-\uDED6\uDF00-\uDFFF]\|\uD86D[\uDC00-\uDF34\uDF40-\uDFFF]\|\uD86E[\uDC00-\uDC1D\uDC20-\uDFFF]\|\uD873[\uDC00-\uDEA1\uDEB0-\uDFFF]\|\uD87A[\uDC00-\uDFE0])+$/	Regular, front-end
Decimals (scientific notation support)	/^[+-]?(\d+([.]\d*)?([eE][+-]?\d+)?\|[.]\d+([eE][+-]?\d+)?)$/	0.0、0.09、4E+4
Numbers only	/^\d+$/	12345678
html tags (loose match)	/<(\w+)[^>]>(.?<\ /\1>)?/	<div id="app"> 2333 </div>、<input type="text">、<br>
Match Chinese characters and Chinese punctuation	/[\u4e00-\u9fa5\|\u3002\|\uff1f\|\uff01\|\uff0c\|\u3001\|\uff1b\|\uff1a\|\u201c\|\u201d\|\u2018\|\u2019\|\uff08\|\uff09\|\u300a\|\u300b\|\u3008\|\u3009\|\u3010\|\u3011\|\u300e\|\u300f\|\u300c\|\u300d\|\ufe43\|\ufe44\|\u3014\|\u3015\|\u2026\|\u2014\|\uff5e\|\ufe4f\|\uffe5]/	匹配中文汉字以及中文标点符号(？！，、；： “ ” ‘ ' （）《》〈〉【】『』「」﹃﹄〔〕 … — ～﹏￥)
qq number correctly formatted	/^[1-9][0-9]{4,10}$/	903013545、9020304
numerical and alphabetic composition	/^[A-Za-z0-9]+$/	james666、haha233hi
English alphabet	/^[a-zA-Z]+$/	Russel
lowercase letters	/^[a-z]+$/	russel
capital letters	/^[A-Z]+$/	ABC、KD
Password strength checksum, minimum 6 digits, including at least 1 uppercase letter, 1 lowercase letter, 1 number, 1 special character	/^\S(?=\S{6,})(?=\S\d)(?=\S[A-Z])(?=\S[a-z])(?=\S[!@#$%^&? ])\S*$/	Kd@curry666
User name checksum, 4 to 16 bits (alpha, numeric, underscore, minus sign)	/^[\w-]{4,16}$/	xiaohua_qq
ip-v4[:port]	/^((\d\|[1-9]\d\|1\d\d\|2[0-4]\d\|25[0-5])\.){3}(\d\|[1-9]\d\|1\d\d\|2[0-4]\d\|25[0-5])(?::(?:[0-9]\|[1-9][0-9]{1,3}\|[1-5][0-9]{4}\|6[0-4][0-9]{3}\|65[0-4][0-9]{2}\|655[0-2][0-9]\|6553[0-5]))?$/	172.16.0.0、172.16.0.0:8080、127.0.0.0、127.0.0.0:998
ip-v6[:port]	/(^(?:(?:(?:[0-9A-Fa-f]{1,4}:){7}[0-9A-Fa-f]{1,4})\|(([0-9A-Fa-f]{1,4}:){6}:[0-9A-Fa-f]{1,4})\|(([0-9A-Fa-f]{1,4}:){5}:([0-9A-Fa-f]{1,4}:)?[0-9A-Fa-f]{1,4})\|(([0-9A-Fa-f]{1,4}:){4}:([0-9A-Fa-f]{1,4}:){0,2}[0-9A-Fa-f]{1,4})\|(([0-9A-Fa-f]{1,4}:){3}:([0-9A-Fa-f]{1,4}:){0,3}[0-9A-Fa-f]{1,4})\|(([0-9A-Fa-f]{1,4}:){2}:([0-9A-Fa-f]{1,4}:){0,4}[0-9A-Fa-f]{1,4})\|(([0-9A-Fa-f]{1,4}:){6}((\b((25[0-5])\|(1\d{2})\|(2[0-4]\d)\|(\d{1,2}))\b)\.){3}(\b((25[0-5])\|(1\d{2})\|(2[0-4]\d)\|(\d{1,2}))\b))\|(([0-9A-Fa-f]{1,4}:){0,5}:((\b((25[0-5])\|(1\d{2})\|(2[0-4]\d)\|(\d{1,2}))\b)\.){3}(\b((25[0-5])\|(1\d{2})\|(2[0-4]\d)\|(\d{1,2}))\b))\|(::([0-9A-Fa-f]{1,4}:){0,5}((\b((25[0-5])\|(1\d{2})\|(2[0-4]\d)\|(\d{1,2}))\b)\.){3}(\b((25[0-5])\|(1\d{2})\|(2[0-4]\d)\|(\d{1,2}))\b))\|([0-9A-Fa-f]{1,4}::([0-9A-Fa-f]{1,4}:){0,5}[0-9A-Fa-f]{1,4})\|(::([0-9A-Fa-f]{1,4}:){0,6}[0-9A-Fa-f]{1,4})\|(([0-9A-Fa-f]{1,4}:){1,7}:))$)\|(^\[(?:(?:(?:[0-9A-Fa-f]{1,4}:){7}[0-9A-Fa-f]{1,4})\|(([0-9A-Fa-f]{1,4}:){6}:[0-9A-Fa-f]{1,4})\|(([0-9A-Fa-f]{1,4}:){5}:([0-9A-Fa-f]{1,4}:)?[0-9A-Fa-f]{1,4})\|(([0-9A-Fa-f]{1,4}:){4}:([0-9A-Fa-f]{1,4}:){0,2}[0-9A-Fa-f]{1,4})\|(([0-9A-Fa-f]{1,4}:){3}:([0-9A-Fa-f]{1,4}:){0,3}[0-9A-Fa-f]{1,4})\|(([0-9A-Fa-f]{1,4}:){2}:([0-9A-Fa-f]{1,4}:){0,4}[0-9A-Fa-f]{1,4})\|(([0-9A-Fa-f]{1,4}:){6}((\b((25[0-5])\|(1\d{2})\|(2[0-4]\d)\|(\d{1,2}))\b)\.){3}(\b((25[0-5])\|(1\d{2})\|(2[0-4]\d)\|(\d{1,2}))\b))\|(([0-9A-Fa-f]{1,4}:){0,5}:((\b((25[0-5])\|(1\d{2})\|(2[0-4]\d)\|(\d{1,2}))\b)\.){3}(\b((25[0-5])\|(1\d{2})\|(2[0-4]\d)\|(\d{1,2}))\b))\|(::([0-9A-Fa-f]{1,4}:){0,5}((\b((25[0-5])\|(1\d{2})\|(2[0-4]\d)\|(\d{1,2}))\b)\.){3}(\b((25[0-5])\|(1\d{2})\|(2[0-4]\d)\|(\d{1,2}))\b))\|([0-9A-Fa-f]{1,4}::([0-9A-Fa-f]{1,4}:){0,5}[0-9A-Fa-f]{1,4})\|(::([0-9A-Fa-f]{1,4}:){0,6}[0-9A-Fa-f]{1,4})\|(([0-9A-Fa-f]{1,4}:){1,7}:))\](?::(?:[0-9]\|[1-9][0-9]{1,3}\|[1-5][0-9]{4}\|6[0-4][0-9]{3}\|65[0-4][0-9]{2}\|655[0-2][0-9]\|6553[0-5]))?$)/i	2031:0000:130f:0000:0000:09c0:876a:130b
hexadecimal color	/^#?([a-fA-F0-9]{6}\|[a-fA-F0-9]{3}\|[a-fA-F0-9]{8}\|[a-fA-F0-9]{4})$/	#f00、#fe9de8、#f8f8f8ff、#f003
Microsignal (wx), 6 to 20 digits, starts with a letter, letter, number, minus sign, underscore	/^[a-zA-Z][-_a-zA-Z0-9]{5,19}$/	github666、kd_-666
Postal code (China)	/^(0[1-7]\|1[0-356]\|2[0-7]\|3[0-6]\|4[0-7]\|5[1-7]\|6[1-7]\|7[0-5]\|8[013-6])\d{4}$/	734500、100101
Chinese and numbers	/^((?:[\u3400-\u4DB5\u4E00-\u9FEA\uFA0E\uFA0F\uFA11\uFA13\uFA14\uFA1F\uFA21\uFA23\uFA24\uFA27-\uFA29]\|[\uD840-\uD868\uD86A-\uD86C\uD86F-\uD872\uD874-\uD879][\uDC00-\uDFFF]\|\uD869[\uDC00-\uDED6\uDF00-\uDFFF]\|\uD86D[\uDC00-\uDF34\uDF40-\uDFFF]\|\uD86E[\uDC00-\uDC1D\uDC20-\uDFFF]\|\uD873[\uDC00-\uDEA1\uDEB0-\uDFFF]\|\uD87A[\uDC00-\uDFE0])\|(\d))+$/	Ha-ha-ha. You're a sixer.
Cannot contain letters	/^[^A-Za-z]*$/	Hello 6, @¥()!
java package name	/^([a-zA-Z_]\w)+([.][a-zA-Z_]\w)+$/	com.bbb.name
mac address	/^(([a-f0-9][0,2,4,6,8,a,c,e]:([a-f0-9]{2}:){4})\|([a-f0-9][0,2,4,6,8,a,c,e]-([a-f0-9]{2}-){4}))[a-f0-9]{2}$/i	38:f9:d3:4b:f5:51、00-0C-29-CA-E4-66
Match consecutively repeated characters	/(.)\1+/	Me Me Me Me, 112233, 11234
Numeric and alphabetic composition and containing both numeric and alphabetic characters	/^(?=.[a-zA-Z])(?=.\d).+$/	I a I 1 I, a to 1
Hong Kong Identity Card	/^[a-zA-Z]\d{6}$[\dA]$$/	K034169(1)
Macau Identity Card	/^[1\|5\|7]\d{6}$\d$$/	5686611(1)
Taiwan Identity Card	/^[a-zA-Z][0-9]{9}$/	U193683453
大写字母，小写字母，数字，特殊符号 `@#$%^&*`~()-+=` 中任意3项密码	/^(?![a-zA-Z]+$)(?![A-Z0-9]+$)(?![A-Z\W_!@#$%^&`~()-+=]+$)(?![a-z0-9]+$)(?![a-z\W_!@#$%^&`~()-+=]+$)(?![0-9\W_!@#$%^&`~()-+=]+$)[a-zA-Z0-9\W_!@#$%^&`~()-+=]/	a1@、A1@、Aa@
All special characters in the ASCII code list.	/[\x21-\x2F\x3A-\x40\x5B-\x60\x7B-\x7E]+/	[、.、^、&3%
Positive integers, not including 0	/^\+?[1-9]\d*$/	1231
Negative integer without 0	/^-[1-9]\d*$/	-1231
integer (math.)	/^(?:0\|(?:-?[1-9]\d*))$/	-1231、123、0
floating point	/^(-?[1-9]\d\.\d+\|-?0\.\d[1-9]\d*\|0\.0+)$/	1.23、-1.01、0.00
floating point (strict)	/^(-?[1-9]\d\.\d+\|-?0\.\d[1-9])$/	1.23、-1.01
email(support Chinese email)	/^[A-Za-z0-9\u4e00-\u9fa5]+@[a-zA-Z0-9_-]+(\.[a-zA-Z0-9_-]+)+$/	90203918@qq.com, nbilly@126.com, 啦啦啦@126.com
Domain name (not web address, does not contain an agreement)	/^([0-9a-zA-Z-]{1,}\.)+([a-zA-Z]{2,})$/	www.baidu.com、baidu.com.cn、api.baidu.com、udtool.com
Officers/enlisted personnel cards	/^[\u4E00-\u9FA5](字第)([0-9a-zA-Z]{4,8})(号?)$/	Military No. 1234567, Sergeant No. P123456X
household register	/(^\d{15}$)\|(^\d{18}$)\|(^\d{17}(\d\|X\|x)$)/	441421999707223115

Introduction to Regular Expressions:

1. A regular expression (often abbreviated as Regex or RE) is a pattern used to match combinations of characters within a string.

2. Regular expressions originated in the fields of theory and computer science and are now widely used in various programming languages and text processing tools for searching, replacing, validating, and parsing text.

3. The basic components of a regular expression include:

(1) Character matching: Matches specific characters, such as letters, numbers, or symbols. For example, `a` matches the character ‘a’.

(2) Metacharacters: Characters with special meanings used to represent specific patterns. For example, `.` matches any single character (except newline characters); `*` indicates that the preceding character may appear zero or more times.

(3) Character sets: Denoted by square brackets [], these match any single character within the set. For example, [abc] matches ‘a’, ‘b’, or ‘c’.

(4) Repetition: Specifies the number of times the preceding element can be repeated. For example: a{3} matches ‘aaa’; a{2,4} matches ‘aa’, ‘aaa’, or ‘aaaa’.

(5) Alternation: Denoted by the pipe symbol |, indicating an “or” relationship. For example, a|b matches ‘a’ or ‘b’.

(6) Grouping: Denoted by parentheses (), this allows multiple elements to be combined into a single unit. Example: (ab) treats ‘ab’ as a single unit.

(7) Anchors: Used to specify the position of a match. For example: ^ denotes the beginning of a string; $ denotes the end of a string.

4. Data source for this page: https://github.com/trentlee0/utools-any-rule/blob/master/src/RULES.js