JavaScript-Regular expression doubts

Regular Expression Manual:

Http://tool.oschina.net/uploads/apidocs/jquery/regexp.html

Regular expression Test address:

http://tool.chinaz.com/regex/

Let's give an example: E-mail

[Email protected]

1.username (example)

([a-z0-9_\.-]+)

[Email protected]

@

3. Company Name (qq.com)

([\da-z\.-]+) \. ([A-z\.] {2,6})

4.^ Match start position!

5.$ Match End Position!

6.[A-ZA-Z] Representative Range

7.{3,16} stands for length

Finally, we correspond to the regular manual, the following regular expression will appear (please remember a word, complex is composed of simple)

/^ ([a-z0-9_\.-]+) @ ([\da-z\.-]+) \. ([A-z\.] {2,6}) $/

JavaScript-Regular expression doubts