1. Regular expressions are often used when building websites. Here are some explanations and examples for your reference and modification only:
2. "^d+$" //Non-negative integer (positive integer + 0)
3. " ^[0-9]*[1-9][0-9]*$" //Positive integer
4. "^((-d+)|(0+))$" //Non-positive integer (negative integer + 0)
5. "^-[0-9]*[1-9][0-9]*$" // Negative integer
6. "^-?d+$" // Integer
7. "^ d+(.d+)?$" //Non-negative floating point number (positive floating point number + 0)
8. "^(([0-9]+.[0-9]*[1-9][0-9 ]*)|([0-9]*[1-9][0-9]*.[0-9]+)|([0-9]*[1-9][0-9]*) )$" //Positive floating point number
9. "^((-d+(.d+)?)|(0+(.0+)?))$" //Non-positive floating point number (negative floating point number + 0)
10. “^(-(([0-9]+.[0-9]*[1-9][0-9]*)|([0-9]*[1-9][0- 9]*.[0-9]+)|([0-9]*[1-9][0-9]*)))$" //Negative floating point number
11. "^(-?d+) (.d+)?$" //Floating point number
12. "^[A-Za-z]+$" //A string consisting of 26 English letters
13. "^[A-Z]+$" // A string consisting of 26 uppercase English letters
14. "^[a-z]+$" //A string consisting of 26 lowercase English letters
15. "^[A-Za-z0-9]+ $" //A string consisting of numbers and 26 English letters
16. "^w+$" //A string consisting of numbers, 26 English letters or underscores
17. "^[w-]+(. [w-]+)*@[w-]+(.[w-]+)+$" //email address
18. "^[a-zA-z]+://(w+(-w+) *)(.(w+(-w+)*))*(?S*)?$" //url
19. /^(d{2}|d{4})-((0([1-9 ]{1}))|(1[1|2]))-(([0-2]([1-9]{1}))|(3[0|1]))$/ // year -Month-Day
20. /^((0([1-9]{1}))|(1[1|2]))/(([0-2]([1-9]{1} ))|(3[0|1]))/(d{2}|d{4})$/ // Month/day/year
21. "^([w-.]+)@(([ [0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}.)|(([w-]+.)+))([a -zA-Z]{2,4}|[0-9]{1,3})(]?)$" //Emil
22. /^((+?[0-9]{2,4} -[0-9]{3,4}-)|([0-9]{3,4}-))?([0-9]{7,8})(-[0-9]+) ?$/ //Phone number
23. "^(d{1,2}|1dd|2[0-4]d|25[0-5]).(d{1,2}|1dd|2[0-4]d|25[ 0-5]).(d{1,2}|1dd|2[0-4]d|25[0-5]).(d{1,2}|1dd|2[0-4]d| 25[0-5])$"
//IP address
24.
25. Regular expression matching Chinese characters: [u4e00-u9fa5]
26. Matching double-byte characters (including Chinese characters): [^x00-xff]
27. Matching blank lines Regular expression: n[s| ]*r
28. Regular expression matching HTML tags: /.*1>|/
29. Regular expression matching leading and trailing spaces: (^s*)|(s *$)
30. Regular expression to match email address: w+([-+.]w+)*@w+([-.]w+)*.w+([-.]w+)*
31. Match URL Regular expression: ^[a-zA-z]+://(\w+(-\w+)*)(\.(\w+(-\w+)*))*(\?\S*)? $
32. Is the matching account legal (starting with a letter, 5-16 bytes allowed, alphanumeric underscores allowed): ^[a-zA-Z][a-zA-Z0-9_]{4,15}$
33 . Matching domestic phone numbers: (d{3}-|d{4}-)?(d{8}|d{7})?
34. Matching Tencent QQ numbers: ^[1-9]*[1- 9][0-9]*$
35.
36.
37. Metacharacters and their behavior in the context of regular expressions:
38.
39. Mark the next character as a special character, or a primitive escape character, or a backreference, or an octal escape character.
40.
41. ^ Matches the beginning of the input string. If the Multiline property of the RegExp object is set, ^ also matches the position after 'n' or 'r'.
42.
43. $ Matches the end position of the input string. If the Multiline property of the RegExp object is set, $ also matches the position before 'n' or 'r'.
44.
45. * Matches the previous subexpression zero or more times.
46.
47. + Matches the previous subexpression one or more times. + is equivalent to {1,}.
48.
49. ? Match the previous subexpression zero or one time. ? Equivalent to {0,1}.
50.
51. {n} n is a non-negative integer that matches a certain number of n times.
52.
53. {n,} n is a non-negative integer that matches at least n times.
54.
55. {n,m} m and n are both non-negative integers, where n 56.
57. ? When the character is immediately followed by any other limiter (*, +, ?, {n}, {n, }, {n,m}), the matching pattern is non-greedy. Non-greedy mode matches as little of the searched string as possible, while the default greedy mode matches as much of the searched string as possible.
58.
59. . Matches any single character except "n". To match any character including 'n', use a pattern like '[.n]'.
60. (pattern) matches pattern and gets this match.
61.
62. (?:pattern) matches pattern but does not get the matching result, which means that this is a non-getting match and is not stored for later use.
63.
64. (?=pattern) Forward lookup, match the search string at the beginning of any string matching pattern. This is a non-fetch match, that is, the match does not need to be fetched for later use.
65.
66. (?!pattern) negative lookup, opposite to (?=pattern)
67.
68. x|y matches x or y.
69.
70. [xyz] character set.
71.
72. [^xyz] Negative character set.
73.
74. [a-z] character range, matches any character within the specified range.
75.
76. [^a-z] Negative character range, matches any character that is not within the specified range.
77.
78. b matches a word boundary, which refers to the position between the word and the space.
79.
80. B matches non-word boundaries.
81.
82. cx matches the control character specified by x.
83.
84. d matches a numeric character. Equivalent to [0-9].
85.
86. D matches a non-numeric character. Equivalent to [^0-9].
87.
88. f matches a form feed. Equivalent to x0c and cL.
89.
90. n matches a newline character. Equivalent to x0a and cJ.
91.
92. r matches a carriage return character. Equivalent to x0d and cM.
93.
94. s matches any whitespace character, including spaces, tabs, form feeds, etc. Equivalent to [fnrtv].
95.
96. S matches any non-whitespace character. Equivalent to [^ fnrtv].
97.
98. t matches a tab character. Equivalent to x09 and cI.
99.
100. v matches a vertical tab character. Equivalent to x0b and cK.
101.
102. w matches any word character including an underscore. Equivalent to '[A-Za-z0-9_]'.
103.
104. W matches any non-word character. Equivalent to '[^A-Za-z0-9_]'.
105.
106. xn matches n, where n is the hexadecimal escape value. The hexadecimal escape value must be exactly two digits long.
107.
108. num matches num, where num is a positive integer. A reference to the match obtained.
109.
110. n identifies an octal escape value or a backreference. n is a backreference if n is preceded by at least n fetched subexpressions. Otherwise, if n is an octal number (0-7), then n is an octal escape value.
111.
112. nm identifies an octal escape value or a backreference. if nm is preceded by at least nm
If a subexpression is obtained, nm is a back reference. If nm is preceded by at least n gets, then n is a backreference followed by the literal m. If none of the previous conditions are met, if
n and m are both octal digits (0-7), then nm will match the octal escape value nm.
113.
114. nml If n is an octal digit (0-3), and m and l are both octal digits (0-7), then matches the octal escape value nml.
115.
116. un matches n, where n is a Unicode character represented by four hexadecimal digits.
117.
118. Regular expression matching Chinese characters: [u4e00-u9fa5]
119.
120. Matching double-byte characters (including Chinese characters): [^x00-xff]
121.
122. match Regular expression for empty lines: n[s| ]*r
123.
124. Regular expression for matching HTML tags: /.*1>|/
125.
126. Regular expression for matching leading and trailing spaces: (^s*)|(s*$)
127.
128. Regular expression matching email addresses: w+([-+.]w+)*@w+([-.]w+)*.w+([- .]w+)*
129.
130. Regular expression matching URL: http://([w-]+.)+[w-]+(/[w- ./?%&=]* )?
131.
132. Use regular expressions to limit the input content of text boxes in web forms:
133.
134. Use
The regular expression limit can only be entered in Chinese: onkeyup="value=value.replace(/[^u4E00-u9FA5]/g,'')"
onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^u4E00-u9FA5]/g,''))"
135.
136. Use regular expressions to limit only Enter full-width characters:
onkeyup="value=value.replace(/[^uFF00-uFFFF]/g,'')"
onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^uFF00-uFFFF]/g,''))"
137.
138. Use regular expressions to limit only Number of inputs
Word: onkeyup="value=value.replace(/[^d]/g,'')
"onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^d]/g,''))"
139.
140. Use regular expressions to limit input numbers and english
Text: onkeyup="value=value.replace(/[W]/g,'')
"onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^d]/g,''))"
141.
142. ======== =Commonly used regular expressions
143.
144.
145.
146. Regular expressions that match Chinese characters: [u4e00-u9fa5]
147.
148. Match double-byte characters (including Chinese characters): [^x00 -xff]
149.
150. Regular expression to match blank lines: n[s| ]*r
151.
152. Regular expression to match HTML tags: /.*1>|/
153.
154. Regular expression matching leading and trailing spaces: (^s*)|(s*$)
155.
156. Regular expression matching IP address: /(d+).(d+).(d+).(d+ )/g //
157.
158. Regular expression matching email addresses: w+([-+.]w+)*@w+([-.]w+)*.w+([-.]w+)*
159.
160. Regular expression matching URL: http://(/[w-]+.)+[w-]+(/[w- ./?%&=]*)? 161.
162. sql statement: ^(select|drop|delete|create|update|insert).*$
163.
164. 1. Non-negative integer: ^d+$
165.
166. 2. Positive integer: ^ [0-9]*[1-9][0-9]*$
167.
168. 3. Non-positive integer: ^((-d+)|(0+))$
169.
170. 4 , Negative integer: ^-[0-9]*[1-9][0-9]*$
171.
172. 5. Integer: ^-?d+$
173.
174. 6. Non-negative float Points: ^d+(.d+)?$
175.
176. 7. Positive floating point number: ^((0-9)+.[0-9]*[1-9][0-9]*)| ([0-9]*[1-9][0-9]*.[0-9]+)|([0-9]*[1-9][0-9]*))$
177 .
178. 8. Non-positive floating point numbers: ^((-d+.d+)?)|(0+(.0+)?))$
179.
180. 9. Negative floating point numbers: ^(-( (Positive floating point regular expression)))$
181.
182. 10. English string: ^[A-Za-z]+$
183.
184. 11. English uppercase string: ^[A-Z]+$
185.
186. 12. English lowercase string: ^[a-z]+$
187.
188. 13. English character and numeric string: ^[A-Za-z0-9]+$
189.
190. 14. Alphanumeric and underlined string: ^w+$
191.
192. 15. E -Mail address: ^[w-]+(.[w-]+)*@[w-]+(.[w-]+)+$
193.
194. 16. URL: ^[a-zA -Z]+://(w+(-w+)*)(.(w+(-w+)*))*(?s*)?$
195. Or: ^http://[A-Za-z0 -9]+.[A-Za-z0-9]+[/=?%-&_~`@[]':+!]*([^""])*$
196.
197. 17 , Postal code: ^[1-9]d{5}$
198.
199. 18. Chinese: ^[u0391-uFFE5]+$
200.
201. 19. Phone number: ^(((d{ 2,3}))|(d{3}-))?((0d{2,3})|0d{2,3}-)?[1-9]d{6,7}(-d{ 1,4})?$
202.
203. 20. Mobile phone number: ^(((d{2,3}))|(d{3}-))?13d{9}$
204.
205 . 21. Double-byte characters (including Chinese characters): ^x00-xff
206.
207. 22. Match leading and trailing spaces: (^s*)|(s*$) (trim function like vbscript)
208.
209. 23. Match HTML tags: .*1>|
210.
211. 24. Match empty lines: n[s| ]*r
212.
213. 25. Extract network links in information (h|H)(r|R)(e|E)(f|F) *= *('|")?(w|\|/|.)+('|"| *|>)?
214.
215. 26. Extract the email address in the information: w+([-+.]w+)*@w+([-.]w+)*.w+([-.]w+)*
216.
217 . 27. Extract the picture link in the information: (s|S)(r|R)(c|C) *= *('|")?(w|\|/|.)+('|"| * |>)?
218.
219. 28. Extract the IP address in the information: (d+).(d+).(d+).(d+)
220.
221. 29. Extract the Chinese mobile phone number in the information: (86)*0*13d{9}
222.
223. 30. Extract the Chinese landline phone number in the information: ((d{3,4})|d{3,4}-|s)?d{ 8}
224.
225. 31. Extract the Chinese phone number in the information (including mobile and landline): ((d{3,4})|d{3,4}-|s)?d{7, 14}
226.
227. 32. Extract the Chinese postal code in the information: [1-9]{1}(d+){5}
228.
229. 33. Extract the floating point number (i.e. decimal) in the information (-?d*).?d+
230.
231. 34. Extract any number in the information: (-?d*)(.d+)? 232.
233. 35. IP: (d+). (d+).(d+).(d+)
234.
235. 36. Telephone area code: /^0d{2,3}$/
236.
237. 37. Tencent QQ number: ^[1-9] *[1-9][0-9]*$
238.
239. 38. Account number (starting with a letter, 5-16 bytes allowed, alphanumeric underscores allowed): ^[a-zA-Z][a- zA-Z0-9_]{4,15}$
240.
241. 39. Chinese, English, numbers and underline: ^[u4e00-u9fa5_a-zA-Z0-9]+$
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