js regular expressions match alphanumeric underscores and so on
- 2020-05-27 04:26:04
- OfStack
1 , 1 The regular expression contains only Chinese characters, Numbers and letters, and the underscore cannot be followed by the beginning and end of the underscore:
^(?!_)(?!.*?_$)[a-zA-Z0-9_\u4e00-\u9fa5]+$ Among them:
^ Matches where the string begins
(?!_) Not to _ At the beginning
(?!.*?_$) Not to _ At the end
[a-zA-Z0-9_\u4e00-\u9fa5]+ At least, 1 Chinese characters, Numbers, letters, underline
$ Matches where the string ends
Put it in front of the program @ , otherwise \\ escape @"^(?!_)(?!.*?_$)[a-zA-Z0-9_\u4e00-\u9fa5]+$"
(or: @"^(?!_)\w*(?<!_)$" or @" ^[\u4E00-\u9FA50-9a-zA-Z_]+$ " )
2 , only contains Chinese characters, Numbers, letters, underline, underline position is not limited:
^[a-zA-Z0-9_\u4e00-\u9fa5]+$
3 , by Numbers, 26 A string of letters or underscores
^\w+$
4 , 2~4 The Chinese characters
@"^[\u4E00-\u9FA5]{2,4}$";
5 ,
^[\w-]+(\.[\w-]+)*@[\w-]+(\.[\w-]+)+$
To use: (Abc)+ To analyze: XYZAbcAbcAbcXYZAbcAb
XYZAbcAbcAbcXYZAbcAb
6 ,
[^\u4E00-\u9FA50-9a-zA-Z_]
34555#5' -->34555#5'
[\u4E00-\u9FA50-9a-zA-Z_] eiieng_89_ ---> eiieng_89_
_';'eiieng_88&*9_ --> _';'eiieng_88&*9_
_';'eiieng_88_&*9_ --> _';'eiieng_88_&*9_
public bool RegexName(string str)
{
bool flag=Regex.IsMatch(str,@"^[a-zA-Z0-9_\u4e00-\u9fa5]+$");
return flag;
}
Regex reg=new Regex("^[a-zA-Z_0-9]+$");
if(reg.IsMatch(s))
{
\\ Comply with the rules
}
else
{
\\ Invalid character
}
That's all for this article, and I hope it will be helpful for you to learn javascript regular expressions.