Home Backend Development PHP Tutorial The most commonly used regular expressions in PHP

The most commonly used regular expressions in PHP

May 25, 2018 pm 02:54 PM
php regular expression

This article will organize and introduce the most commonly used regular expressions in PHP. It has a very good reference value. Let’s take a look at it with the editor.

1. Expression of check numbers

Number: ^[0-9] *$

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

At least n-digit number: ^\d{n,}$

m-n-digit number :^\d{m,n}$

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

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

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

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

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

has 1 ~Positive real number with 3 decimal places: ^[0-9] (.[0-9]{1,3})?$

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

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

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

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

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

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

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

2. Expression of check characters

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

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

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

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

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

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

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

consists of A string consisting of numbers, 26 English letters or underscores: ^\w $ or ^\w{3,20}$

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

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

You can enter characters containing ^%&',;=?$\": [^%&',;=?$\x22]

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

3. Special requirement expression

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

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

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

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}$

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

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

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

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}?$

Account number Legal (starts with a letter, allows 5-16 bytes, allows alphanumeric underscores): ^[a-zA-Z][a-zA-Z0-9_]{4,15}$

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

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

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

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

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

Money input format:

  • There are four acceptable representations of money: "10000.00" and "10,000.00", and "10000" and "10,000" without "cents": ^[1-9][0-9]* $

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

  • ##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]*)$

  • 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 as well, because money cannot be negative. What we need to add below is the possible decimal part: ^[0-9] (.[0-9] )?$

  • 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})?$

  • 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})?$

  • This allows the user 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}) ?$

  • 1 to 3 digits, followed by any number of commas and 3 digits, the commas become optional instead of required: ^([0-9] |[0-9]{1,3 }(,[0-9]{3})*)(.[0-9]{1,2})?$

  • Note: This is the final result, don’t Forgot "" can be replaced with "*". If you think empty strings are acceptable (strange, why?) Finally, don’t forget to remove the backslash when using the function. Common mistakes are here

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

中文Regular expression of characters: [\u4e00-\u9fa5]

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

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

Regular expression for HTML tags Expression: <(\S*?)[^>]*>.*?|<.*? /> (The version circulating on the Internet is too bad, the above one can only Partially, there is still nothing we can do about complex nested tags)

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

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

China postal code: [1-9]\d{5}(?!\d) (China postal code is 6 digits)

IP address: \d \.\d \.\d \.\d (useful when extracting IP address)

The above is the entire content of this article, I hope it will be helpful to everyone learning helps.


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##Regular\B and in expression \bDetailed explanation of usage steps

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