The regular expression testing tool provides you with JS regular expression verification, regular expression verification, regular expression verification, regular expression testing tools, which can be used to customize regular expressions to extract text content, validate arbitrary regular expressions, extract URLs from regular expressions, and format regular expressions online. I hope it will be helpful to everyone.
The role of regular expressions
A regular expression is a text pattern that includes ordinary characters (for example, letters between a and z) and special characters (called "metacharacters"). Regular expressions use a single string to describe and match a series of strings that match a certain syntactic rule. Regular expressions are cumbersome, but they are powerful. After learning them, they will give you an absolute sense of achievement in addition to improving efficiency. Many programming languages support string operations using regular expressions.
common metacharacters| code | explain |
|---|---|
| . | Matches any character except newline characters |
| \w | Match letters or numbers or underscores |
| \s | Matches any whitespace |
| \d | match number |
| \b | Match the beginning or end of a word |
| ^ | Start of matching string |
| $ | Match end of string |
common qualifier| Code/Syntax | explain |
|---|---|
| * | Repeat zero or more times |
| + | Repeat one or more times |
| ? | Repeat zero or once |
| {n} | Repeat n times |
| {n,} | Repeat n or more times |
| {n,m} | Repeat n to m times |
common antonym| Code/Syntax | explain |
|---|---|
| \W | Matches any character that is not a letter, number, underscore, or kanji |
| \S | Matches any character that is not a whitespace character |
| \D | Matches any non-numeric characters |
| \B | Match is not where words begin or end |
| [^x] | Matches any character except x |
| [^aeiou] | Matches any character except the letters aeiou |
| character | describe |
|---|---|
| ^\d+$ | Match non-negative integers (positive integers + 0) |
| //Matches the integer ^\d+(\.\d+)?$ | Match non-negative floating-point numbers (positive floating-point numbers + 0) |
| ^(([0-9]+\.[0-9]*[1-9][0-9]*)|([0-9]*[1-9][0-9]*\.[0-9]+)|([0-9]*[1-9][0-9]*))$ | //Match positive floating-point numbers |
| ^((-\d+(\.\d+)?)|(0+(\.0+)?))$ | Match non-positive floating-point numbers (negative floating-point numbers + 0) |
| ^(-(([0-9]+\.[0-9]*[1-9][0-9]*)|([0-9]*[1-9][0-9]*\.[0-9]+)|([0-9]*[1-9][0-9]*)))$ | //match negative floating-point numbers |
| ^(-?\d+)(\.\d+)?$ | //match floating-point numbers |
| ^[A-Za-z]+$ | Match a string of 26 English letters |
| ^[A-Z]+$ | Matches a string of 26 English letters |
| ^[a-z]+$ | Matches a string of 26 lowercase letters |
| ^[A-Za-z0-9]+$ | Match a string of numbers and 26 letters |
| ^\w+$ | Matches a string consisting of numbers, 26 letters, or underscores |
| ^[\w-]+(\.[\w-]+)*@[\w-]+(\.[\w-]+)+$ | //match email address |
| ^[a-zA-z]+://匹配(\w+(-\w+)*)(\.(\w+(-\w+)*))*(\?\S*)?$ | //match url |
| [\u4e00-\u9fa5] | Regular expressions that match Chinese characters |
| [^\x00-\xff] | Match double-byte characters (including Chinese characters) |
| \n[\s| ]*\r | Regular expression that matches blank lines |
| /<(.*)>.*<\/>|<(.*)\/>/ | Regular expressions that match HTML tags |
| (^\s*)|(\s*$) | Regular expressions that match end-to-end spaces |
| \w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)* | Regular expression for matching email addresses |
| ^[a-zA-z]+://(\w+(-\w+)*)(\.(\w+(-\w+)*))*(\?\S*)?$ | Regular Expression Matching URL |
| ^[a-zA-Z][a-zA-Z0-9_]{4,15}$ | Match whether the account is legal (start with a letter, allow 5-16 bytes, allow alphanumeric underscores) |
| (\d{3}-|\d{4}-)?(\d{8}|\d{7})? | Match domestic phone numbers |
| ^[1-9]*[1-9][0-9]*$ | Match Tencent QQ number |
