The most comprehensive collection of commonly used regular expressions - including check digits, characters, some special requirements, etc.

1. Expression of check digits

1 Number: ^[0-9]*$

2 n-digit number: ^\d{n}$

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

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

5 Zero and non-zero Numbers at the beginning: ^(0|[1-9][0-9]*)$

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

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

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

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

10 Positive real numbers with 1~3 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 length 3-20: ^.{3,20 }$

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

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

6 A string consisting of 26 lowercase English letters: ^[a-z]+$

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

8 A string consisting of numbers, 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 Formula

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

6 Domestic phone 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, 5-16 bytes allowed, alphanumeric underscores allowed) ：^[a-zA-Z][a-zA-Z0-9_]{4,15}$

10 Password (starts with a letter, length is between 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, and the length is 8- between 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 money representation forms we can accept: "10000.00" and "10,000.00", and "10000" and "10,000" without "cent": ^[1-9][0-9]*$

17 2. This means any number that does not start with 0 , however, this also means that a character "0" is not passed, 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. Also remove the negative sign, because money cannot be negative. What we need to add below is to illustrate the possible decimal part: ^[0-9]+(.[0-9]+)?$

20 5. It must be noted that 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 after the decimal point Bit, if you think it's too harsh, you can do this: ^[0-9]+(.[0-9]{1,2})?$

22 7. This allows the user to write only one decimal place. Now we should consider the comma in the number. 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, the comma becomes optional, not 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 it when using functions. Remove the backslash, the common errors 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, it can be used to calculate the length of a string (a double-byte character is counted as 2, and an 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: <(\S*?)[^>]*>.*?< /\1>|<.*? /> (The version circulating on the Internet is too bad, the above one is only partially effective, and it is still powerless for complex nested tags)

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

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

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

More and most comprehensive collection of commonly used regular expressions—— For related articles including check digits, characters, some special requirements, etc. please pay attention to the PHP Chinese website!