Metacharacters
Metacharacter (Metacharacter) is to have a special meaning of characters:
| Metacharacters | description |
|---|---|
| . | Find a single character, except for line breaks and line endings. |
| \w | Find a word character. |
| \W | Find a non-word character. |
| \d | Find figures. |
| \D | Finding non-numeric characters. |
| \s | Find a blank character. |
| \S | Find a non-whitespace characters. |
| \b | Find matching located the beginning or end of a word. |
| \B | Find a match not at the beginning or end of a word. |
| \0 | Find NUL characters. |
| \n | Find newline. |
| \f | Find feed character. |
| \r | Find carriage return. |
| \t | Find tab. |
| \ v | Find vertical tab. |
| \xxx | Find octal number xxx defined characters. |
| \ xdd | Find a hexadecimal number dd illegal characters. |
| \uxxxx | Find a hexadecimal number xxxx provisions of Unicode characters. |
/ *
* Check whether the string a little.
* Represents any character
* in the regular expression \ represents the escape character
* \. To represent.
* \\ to represent \
* Note
* When using the constructor, because of his parameter is a string, and \ is the escape character
* If you want to use \ you need to use \\ instead!
* /
\ W is arbitrary, letters, numbers, _ equivalent to [A-z1-9_]
\ W In addition to letters, numbers, corresponding to _ [^ A-z1-9_]
\ D is an arbitrary number corresponding to [0-9]
\ D is in addition to the digital [^ 0-9]
\ S is a space meant
\ S in addition to the space
or
\ B is the meaning of a word boundary
\ B is in addition to the meaning of a word boundary
A space to accept user input and to remove the front and back of
var str = prompt ( "Please enter your user name")
str = str.replace (/ ^ \ S * | \ * $ S / G, "")
Let no spaces / ^ before the string \ s * /
get behind the string with no spaces / \ s * $ /
