Common regular expressions and commentaries-learning regular expressions

Matching regular expressions for Chinese characters: [\U4E00-\U9FA5]
Commentary: Matching Chinese is really a headache, with this expression will be easy to do
Match Double-byte characters (including Chinese characters): [^\x00-\xff]
Commentary: can be used to compute the length of a string (a double-byte character length meter 2,ascii 1 characters)
A regular expression that matches a blank row: \n\s*\r
Commentary: can be used to delete blank lines
Regular expression:< matching HTML tags (\s*?) [^>]*>.*?</\1>|<.*? />
Commentary: 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*$
Commentary: A useful expression that can be used to delete white-space characters (including spaces, tabs, page breaks, and so on) at the end of a line at the beginning
Regular expression matching an email address: \w+ ([-+.] \w+) *@\w+ ([-.] \w+) *\.\w+ ([-.] \w+) *
Commentary: Form validation is useful
Regular expressions that match URL URLs: [a-za-z]+://[^\s]*
Commentary: Online circulation of the version of the function is very limited, which can meet the basic requirements
Match account number is legal (beginning of letter, allow 5-16 bytes, allow alphanumeric underline): ^[a-za-z][a-za-z0-9_]{4,15}$
Commentary: Form validation is useful
Match domestic phone number: \d{3}-\d{8}|\d{4}-\d{7}
Commentary: Match form such as 0511-4405222 or 021-87888822
Matching Tencent QQ Number: [1-9][0-9]{4,}
Commentary: Tencent QQ number starting from 10000
Match China ZIP Code: [1-9]\d{5} (?! \d)
Commentary: China postal code is 6 digits
Matching ID: \d{15}|\d{18}
Commentary: China's ID card is 15-or 18-digit
Matching IP address: \d+\.\d+\.\d+\.\d+
Commentary: Useful when extracting IP addresses
Match a specific number:
^[1-9]\d*$//Matching positive integer
^-[1-9]\d*$//matching negative integers
^-? [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 numbers
^-([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+|0$//matching non-positive floating-point numbers (negative floating-point number + 0)
Commentary: useful when dealing with large amounts of data, pay attention to corrections when applied
Match a specific string:
^[a-za-z]+$//Match a string of 26 English letters
^[a-z]+$//Match a string of 26 uppercase letters
^[a-z]+$//Match string consisting of 26 lowercase letters
^[a-za-z0-9]+$//Match a string of numbers and 26 English letters
^\w+$//Match A string of numbers, 26 English letters, or underscores
Commentary: Some of the most basic and commonly used expressions