Favorite list of frequently used regular expressions

Various regular expressions are very common in software development. But sometimes when you need some expressions, you can’t think of them for a while, so you just put some commonly used expressions together, so that you will need them later. When the time comes, just copy it directly, avoid searching Googles again, and there is no need to spend more time on this. This way, you can better free your brain capacity and use it to remember more important things.😄

Number express

Digits(zero or more ).
```
^[0-9]*$
```
N digits.
```
^\d{n}$
```
At least n digits.
```
^\d{n,}$
```
M to N digits.
```
^\d{m,n}$
```
Numbers starting with zero and non-zero.
```
^(0|[1-9][0-9]*)$
```
Non-zero leading number with up to two decimal places.
```
^([1-9][0-9]*)+(\.[0-9]{1,2})?$
```
Positive or negative numbers with 1-2 decimal places.
```
^(\-)?\d+(\.\d{1,2})$
```
Positive, negative, and decimal numbers.
```
^(\-|\+)?\d+(\.\d+)?$
```
Positive real numbers with two decimal places.
```
^[0-9]+(\.[0-9]{2})?$
```
Positive real numbers with 1 to 3 decimal places.
```
^[0-9]+(\.[0-9]{1,3})?$
```

Non-zero Positive integer.

^[1-9]\d*$
^([1-9][0-9]*){1,3}$
^\+?[1-9][0-9]*$

Non-zero negative integer.
```
^\-[1-9][]0-9"*$ 
^-[1-9]\d*$
```
Non-negative integer.
```
^\d+$ 
^[1-9]\d*|0$
```
Non-positive integer.
```
^-[1-9]\d*|0$
^((-\d+)|(0+))$
```

Non-negative floating point number.

^\d+(\.\d+)?$
^[1-9]\d*\.\d*|0\.\d*[1-9]\d*|0?\.0+|0$

Noe-positive floating point number.

^((-\d+(\.\d+)?)|(0+(\.0+)?))$
^(-([1-9]\d*\.\d*|0\.\d*[1-9]\d*))|0?\.0+|0$

Positive floating point number.

^[1-9]\d*\.\d*|0\.\d*[1-9]\d*$
^(([0-9]+\.[0-9]*[1-9][0-9]*)|([0-9]*[1-9][0-9]*\.[0-9]+)|([0-9]*[1-9]* [0-9]*))$

Nagetive floating point number.

^-([1-9]\d*\.\d*|0\.\d*[1-9]\d*)$
^(-(([0-9]+\.[0-9]*[1-9][0-9]*)|([0-9]*[1-9][0-9]*\.[0-9]+)|([0-9]*- [1-9][0-9]*)))$

Floating point number.

^(-?\d+)(\.\d+)?$ 或 ^-?([1-9]\d*\.\d*|0\.\d*[1-9]\d*|0?\.0+|0)$

Character express

Basic Chinese(zero or more).
```
^[\u4e00-\u9fa5]{0,}$
```

English and numbers.

^[A-Za-z0-9]+$
^[A-Za-z0-9]{4,40}$ # length 4-40

Any character except newline \n of length 3-20.
```
^.{3,20}$
```
A string of 26 english letters.
```
^[A-Za-z]+$
```
A string of 26 uppercase english letters.
```
^[A-Z]+$
```
A string of 26 lowercase english letters.
```
^[a-z]+$
```
A string of numbers and 26 english letter.
```
^[A-Za-z0-9]+$
```
A string composed of numbers, 26 english letters or underscores.
```
^\w+$
^\w{3,20}$ # length 3-20
```
Basic Chinese, English, numbers including underscore.
```
^[\u4E00-\u9FA5A-Za-z0-9_]+$
```
Basic Chinese, English, number but not including ubderscores and other symbols.
```
^[\u4E00-\u9FA5A-Za-z0-9]+$ 
^[\u4E00-\u9FA5A-Za-z0-9]{2,20}$
```
Characters containing &%’,;”=?$ there are not allowed.
```
[^%&',;=?$]+
```
Characters containing ~ are not allowed.
```
[^~]+
```

Currency expression

Match numbers that start with non-zero.
```
^[1-9][0-9]*$
```
Match numbers zero or start with non-zero.
```
^(0|[1-9][0-9]*)$
```
Match numbers negative, zero or start with non-zero.
```
^(0|-?[1-9][0-9]*)$
```
Match amount expression.
```
^[0-9]+(\.[0-9]+)?$
```
Match amount expression with must have 2 decimal places.
```
^[0-9]+(\.[0-9]{2})?$
```
Match amount expression with must have 1~2 decimal places.
```
^[0-9]+(\.[0-9]{1,2})?$
```
Amount as a 3-digit with must have comma-separated expression and have 1~2 decimal places.
```
^[0-9]{1,3}(,[0-9]{3})*(.[0-9]{1,2})?$ 
```
Amount as a 3-digit not must comma-separated expression and have 1~2 decimal places,Only all a 3-digit comma-separated or all not comma-separated.
```
^([0-9]+|[0-9]{1,3}(,[0-9]{3})*)(.[0-9]{1,2})?$
```
Basic Chinese.
```
[\u4e00-\u9fa5]
```
Duble-byte characters expression.
```
[^\x00-\xff]
```
Blank newline expression.
```
\n\s*\r
```
Regular expression for HTML tags.
```
<(\S*?)[^>]*>.*?|<.*? />
```
Regular expression for leading and trailing whitespace characters.
```
^\s*|\s*$
(^\s*)|(\s*$)
```
Tencet QQ Account.
```
[1-9][0-9]{4,}
```
China Postal Code.
```
[1-9]\d{5}(?!\d) 
```

IPv4 regular expression.

((2(5[0-5]|[0-4]\d))|[0-1]?\d{1,2})(\.((2(5[0-5]|[0-4]\d))|[0-1]?\d{1,2})){3}

Special expression

Matches characters starting with - or [- on each line.
```
^- |^\[- 
```

Email regular expression.

^\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$

Domain name regular expression.

[a-zA-Z0-9][-a-zA-Z0-9]{0,62}(\.[a-zA-Z0-9][-a-zA-Z0-9]{0,62})+\.?

Internet URL regular expression.

[a-zA-z]+://[^\s]*
^http://([\w-]+\.)+[\w-]+(/[\w-./?%&=]*)?$ #Just start with http

China mobile phone regular expression.

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

China mobile phone regular expression for XXX-XXXXXXX.
```
^(\(\d{3,4}-)|\d{3.4}-)?\d{7,8}$
```
China fixed phone.
```
\d{3}-\d{8}|\d{4}-\d{7}
```
Can support including mobile phone number, {3,4} area code - {7,8} direct number + {1,4} extension, {7,8} direct number + {1,4} extension
```
((\d{11})|^((\d{7,8})|(\d{4}|\d{3})-(\d{7,8})|(\d{4}|\d{3})-(\d{7,8})-(\d{4}|\d{3}|\d{2}|\d{1})|(\d{7,8})-(\d{4}|\d{3}|\d{2}|\d{1}))$)
```
Chinese ID number, the last digit may by X.
```
(^\d{15}$)|(^\d{18}$)|(^\d{17}(\d|X|x)$)
```
Start with a letters,allow 5-16 bytes, allow alphanumeric underscore.
```
^[a-zA-Z][a-zA-Z0-9_]{4,15}$
```
Start with a letters, the length is between 6 and 18, and can only contain letters, numbers and underscores.
```
^[a-zA-Z]\w{5,17}$
```
Strong password,Must contain a combination of uppercase and lowercase letters and numbers, cannot use special characters, and the length is between 8-10.
```
^(?=.*\d)(?=.*[a-z])(?=.*[A-Z])[a-zA-Z0-9]{8,10}$
```
Strong password,Must contain a combination of uppercase and lowercase letters and numbers,special characters can be used, and the length is between 8-10.
```
^(?=.*\d)(?=.*[a-z])(?=.*[A-Z]).{8,10}$
```
Data format regular expression.
```
^\d{4}-\d{1,2}-\d{1,2}
```
Month of regular expression.
```
^(0?[1-9]|1[0-2])$
```
Every day of regular expression.
```
^((0?[1-9])|((1|2)[0-9])|30|31)$
```

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Anig Kus

Technologist | Author | Interested in Distributed Technology and Cloud Native Fields

Favorite list of frequently used regular expressions

Number express

Character express

Currency expression

Special expression