Summary of some commonly used regular expressions

This article mainly shares a summary of some commonly used regular expressions with you. It has a good reference value and I hope it will be helpful to everyone. Let’s follow the editor to take a look, I hope it can help everyone.

Use symbols to describe writing rules: / Write the regular expression in the middle /

^: match the beginning, $: match the end; /^ve//ve$ starting with ve / ends with ve

\d: an arbitrary number

\w: an arbitrary number or letter

\s: any string

{n}: Repeat the expression on the left n times

{m,n}: Repeat the expression on the left at least m times and at most n times
{m, }: Repeat the expression on the left Repeat at least m times, up to no limit

+: The expression on the left appears at least once, up to no limit, equivalent to {1,}

*: The expression on the left, at least Appears 0 times, no limit at most, equivalent to {0,}

?: The expression on the left appears at least 0 times, appears at most 1 time, equivalent to {0,1}

[a,b,c]: can only take one of the contents in square brackets

[a-z] or [1-9]: take one of the contents in the range

|: represents or; ( ): Priority; \: Escape--"\( \)" is the parentheses that are going to appear, and they need to be escaped

Commonly used regular rules Expression:

1. Expression of check number

1 Number: ^[0-9]*$

2 Number with n digits: ^\d{n}$

3 Number with at least n digits: ^\d{n,}$

4 Number with m-n digits: ^\ d{m,n}$

5 Numbers starting with zero and non-zero: ^(0|[1-9][0-9]*)$

6 Numbers starting with non-zero Numbers with up to two decimal places: ^([1-9][0-9]*)+(.[0-9]{1,2})?$

7 Positive or negative numbers with 1-2 decimal places: ^(\-)?\d+(\.\d{1,2})?$

8 Positive numbers, negative numbers, and Decimal: ^(\-|\+)?\d+(\.\d+)?$

9 Positive real number with two decimal places: ^[0-9]+(.[0-9] {2})?$

10 Positive real numbers with 1 to 3 decimal places: ^[0-9]+(.[0-9]{1,3})?$

11 Non-zero positive integer: ^[1-9]\d*$ or ^([1-9][0-9]*){1,3}$ or ^\+?[1-9][ 0-9]*$

##12 Non-zero negative integer: ^\-[1-9][]0-9"*$ or ^-[1-9]\d*$

13 Non-negative integer: ^\d+$ or ^[1-9]\d*|0$

14 Non-positive integer: ^-[1-9]\d*|0$ or ^((-\d+)|(0+))$

15 Non-negative floating point number: ^\d+(\.\d+)?$ or ^[1-9]\d*\.\ d*|0\.\d*[1-9]\d*|0?\.0+|0$

16 Non-positive floating point number: ^((-\d+(\.\d+ )?)|(0+(\.0+)?))$ or ^(-([1-9]\d*\.\d*|0\.\d*[1-9]\d* ))|0?\.0+|0$

17 Positive floating point number: ^[1-9]\d*\.\d*|0\.\d*[1-9]\ d*$ or ^(([0-9]+\.[0-9]*[1-9][0-9]*)|([0-9]*[1-9][0-9 ]*\.[0-9]+)|([0-9]*[1-9][0-9]*))$

18 Negative floating point number: ^-([1- 9]\d*\.\d*|0\.\d*[1-9]\d*)$ or ^(-(([0-9]+\.[0-9]*[1- 9][0-9]*)|([0-9]*[1-9][0-9]*\.[0-9]+)|([0-9]*[1-9] [0-9]*)))$

19 Floating point number: ^(-?\d+)(\.\d+)?$ or ^-?([1-9]\d*\. \d*|0\.\d*[1-9]\d*|0?\.0+|0)$

2. Expression of check characters

1 Chinese characters: ^[\u4e00-\u9fa5]{0,}$

2 English and numbers: ^[A-Za-z0-9]+$ or ^[A-Za -z0-9]{4,40}$

3 All characters with a length of 3-20: ^.{3,20}$

4 Characters consisting of 26 English letters String: ^[A-Za-z]+$

5 String consisting of 26 uppercase English letters: ^[A-Z]+$

6 Composed of 26 lowercase English letters String: ^[a-z]+$

7 String composed of numbers and 26 English letters: ^[A-Za-z0-9]+$

8 composed of numbers , a string of 26 English letters or underscores: ^\w+$ or ^\w{3,20}$

9 Chinese, English, numbers including underscores: ^[\u4E00-\u9FA5A-Za-z0-9_]+$

10 Chinese, English, numbers but not including underscores and other symbols: ^[\ u4E00-\u9FA5A-Za-z0-9]+$ or ^[\u4E00-\u9FA5A-Za-z0-9]{2,20}$

11 can be entered containing ^%&',; =?$\" and other characters: [^%&',;=?$\x22]+

12 It is forbidden to enter characters containing ~: [^~\x22]+

3. Expression of special needs

1 Email address: ^\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+ ([-.]\w+)*$

2 Domain name: [a-zA-Z0-9][-a-zA-Z0-9]{0,62}(/.[a-zA -Z0-9][-a-zA-Z0-9]{0,62})+/.?

3 InternetURL: [a-zA-z]+://[^\s] * or ^http://([\w-]+\.)+[\w-]+(/[\w-./?%&=]*)?$

4 Mobile phone number :^(13[0-9]|14[5|7]|15[0|1|2|3|5|6|7|8|9]|18[0|1|2|3|5| 6|7|8|9])\d{8}$

5 Phone number("XXX-XXXXXXX", "XXXX-XXXXXXXX", "XXX-XXXXXXX", "XXX-XXXXXXXX", " XXXXXXX" and "XXXXXXXX): ^(\(\d{3,4}-)|\d{3.4}-)?\d{7,8}$

6 Domestic telephone number (0511- 4405222, 021-87888822):\d{3}-\d{8}|\d{4}-\d{7}

7 ID number (15 digits, 18 digits): ^ \d{15}|\d{18}$

8 Short ID number (numbers, letters ending in x): ^([0-9]){7,18}(x|X)? $ or ^\d{8,18}|[0-9x]{8,18}|[0-9X]{8,18}?$

9 Is the account legal (starting with a letter, 5 allowed -16 bytes, alphanumeric underscores allowed): ^[a-zA-Z][a-zA-Z0-9_]{4,15}$

10 Password (starts with a letter, length is 6 ~18, can only contain letters, numbers and underscores): ^[a-zA-Z]\w{5,17}$

11 Strong password (must contain a combination of uppercase and lowercase letters and numbers) , special characters cannot be used, the length is between 8-10): ^(?=.*\d)(?=.*[a-z])(?=.*[A-Z]).{8,10}$

12 Date format: ^\d{4}-\d{1,2}-\d{1,2}

13 12 months of the year (01～09 and 1 ~12): ^(0?[1-9]|1[0-2])$

14 31 days of a month (01~09 and 1~31): ^((0?[ 1-9])|((1|2)[0-9])|30|31)$

15 Money input format:

16 1. There are four forms of money representation that we can accept: "10000.00" and "10,000.00", and "10000" and "10,000" without "cents": ^[1-9][0-9] *$

17 2. This means any number that does not start with 0, but it also means that a character "0" does not pass, so we use the following form: ^(0|[1- 9][0-9]*)$

18 3. A 0 or a number that does not start with 0. We can also allow a negative sign at the beginning: ^(0|-?[1-9 ][0-9]*)$

19 4. This means a 0 or a number that may be negative and does not start with 0. Let the user start with 0. Remove the negative sign too, Because money can’t be negative. What we need to add below is the possible decimal part: ^[0-9]+(.[0-9]+)?$

20 5. Must be explained The thing is, there should be at least 1 digit after the decimal point, so "10." is not passed, but "10" and "10.2" are passed: ^[0-9]+(.[0-9]{2 })?$

21 6. In this way, we stipulate that there must be two decimal places after the decimal point. If you think it is too harsh, you can do this: ^[0-9]+(.[0-9]{1, 2})?$

22 7. This allows users to write only one decimal place. Next we should consider commas in numbers, we can do this: ^[0-9]{1,3}( ,[0-9]{3})*(.[0-9]{1,2})?$

23 8.1 to 3 numbers, followed by any number of commas + 3 numbers, comma Become optional instead of required: ^([0-9]+|[0-9]{1,3}(,[0-9]{3})*)(.[0-9]{1, 2})?$

24 Note: This is the final result, don’t forget that "+" can be replaced with "*" if you think an empty string is acceptable (strange, why?) Finally, Don't forget to remove the backslash when using the function. Common mistakes are here

25 xml file: ^([a-zA-Z]+-?)+[a-zA-Z0 -9]+\\.[x|X][m|M][l|L]$

26 Regular expression for Chinese characters: [\u4e00-\u9fa5]

27 Double-byte characters: [^\x00-\xff] (including Chinese characters, can be used to calculate the length of the string (the length of a double-byte character is counted as 2, and the ASCII character is counted as 1))

28 Regular expression for blank lines: \n\s*\r (can be used to delete blank lines)

29 Regular expression for HTML tags: ] *>.*?\1>|<.> (The version circulating on the Internet is too bad, the above one can only partially work, and it is still powerless for complex nested tags)

30 Regular expression for leading and trailing blank characters: ^\s*|\s*$ or (^\s*)|(\s*$) (can be used to delete blank characters at the beginning and end of the line (including spaces, table characters, page feeds, etc.), very useful expressions)

31 Tencent QQ number: [1-9][0-9]{4,} (Tencent QQ number starts from 10000)

32 China Postal Code: [1-9]\d{5}(?!\d) (China Postal Code is 6 digits) 33 IP Address: \d+\.\d+\.\d+\.\ d+ (useful when extracting IP address) 34 IP address: ((?:(?:25[0-5]|2[0-4]\\d|[01]?\\d?\\d)\\ .){3}(?:25[0-5]|2[0-4]\\d|[01]?\\d?\\d))

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