Common PHP Regular expressions and grammatical annotations

Common PHP Regular expressions and grammatical annotations:





a regular expression that matches a Chinese character: [U4e00-u9fa5]


annotation: Match Chinese is really a headache, with this expression is good to do





match Double-byte characters (including Chinese characters): [^x00-xff]


Note: Can be used to compute the length of a string (a two-byte character-length meter 2,ascii character count 1)





a regular expression that matches a blank row: Ns*r


Note: Can be used to delete blank rows





Regular expression:< matching HTML tags (s*?) [^>]*>.*?| <.*? />


Note: The online version is too bad, the above can only match the part of the complex nested tags still powerless





a regular expression that matches the end-end whitespace character: ^s*|s*$


Note: A useful expression that can be used to delete white space characters (including spaces, tabs, page breaks, and so on) that are at the end of a line beginning





a regular expression matching an email address: w+ ([-+.] w+) *@w+ ([-.] w+) *.w+ ([-.] w+) *


Note: Form validation is practical





a regular expression that matches URL URLs: [a-za-z]+://[^s]*


Note: Online circulation of the version of the function is very limited, above this basic can meet the demand





Match account number is legal (beginning of letter, allow 5-16 bytes, allow alphanumeric underline): ^[a-za-z][a-za-z0-9_]{4,15}$


Note: Form validation is practical





matching domestic phone number: D{3}-d{8}|d{4}-d{7}


annotation: Match form such as 0511-4405222 or 021-87888822





matching Tencent QQ number: [1-9][0-9]{4,}


annotation: Tencent QQ number starts from 10000





matching China zip code: [1-9]d{5} (?! d)


Note: China's postal code is 6 digits





matching ID: d{15}|d{18}


NOTE: China's ID card is 15-or 18-bit





Matching IP address: d+.d+.d+.d+


Note: Useful when extracting IP addresses





matches a specific number:


^[1-9]d*$//matching positive integer


^-[1-9]d*$//matching negative integer


^-? [1-9]d*$//matching integer


^[1-9]d*|0$//matching nonnegative integer (positive integer + 0)


^-[1-9]d*|0$//matching non positive integer (negative integer + 0)


^[1-9]d*.d*|0.d*[1-9]d*$//matching positive floating-point number


^-([1-9]d*.d*|0.d*[1-9]d*) $///matching negative floating-point number


    ^-? ([1-9]d*.d*|0.d*[1-9]d*|0?. 0+|0) $///matching floating-point number


^[1-9]d*.d*|0.d*[1-9]d*|0? 0+|0$//matching nonnegative floating-point number (positive floating-point number + 0)


^ (-([1-9]d*.d*|0.d*[1-9]d*)) | 0+|0$//matching non-positive floating-point numbers (negative floating-point number + 0)


annotation: Useful when dealing with a large amount of data, pay attention to correction when applying





match a specific string:


^[a-za-z]+$//Match a string of 26 English letters


^[a-z]+$//Match a string consisting of 26 uppercase letters


^[a-z]+$//matches a string consisting of 26 lowercase letters


^[a-za-z0-9]+$//Match a string of numbers and 26 English letters


^w+$//matches a string of numbers, 26 English letters, or underscores


annotation: The most basic and most commonly used expressions