Regular Expression summary, Regular Expression

Regular Expression summary, Regular Expression

1. Match tag a and its url:

Regex regA = new Regex(@"<a[\s]+[^<>]*href=(?:""|')([^<>""']+)(?:""|')[^<>]*>([^<>]+)</a>", RegexOptions.IgnoreCase);

Note: In the above regular expression,

Used to match various attributes before and after the href attribute:

[^<>]*

Used to match the url in the middle of the href attribute quotation marks:

([^<>""']+)

Used to match the content between tags:

([^<>]+)

 

2. Match the img tag and its url:

 Regex regImg = new Regex(@"]*src=(?:""|')([^<>""']+(?:\.jpg|\.jpeg|\.png|\.gif))(?:""|')[^<>]*>", RegexOptions.IgnoreCase);

3. matching the tag and the content in the tag center:

reg = new Regex(@"<dl class=""ksDl"">(?:(?!</dl>)[\s\S])*</dl>", RegexOptions.IgnoreCase);

Note: When the html string is as follows, it can be matched in two places,

<Dl class = "ksDl"> <div> test </div> </dl> <dl class = "ksDl"> <div> test </div> </dl>

If the regular expression is written like this:

reg = new Regex(@"<dl class=""ksDl"">[\s\S]*</dl>", RegexOptions.IgnoreCase);

Only one matching place is allowed. Pay attention to the functions of the following parts, which are excluded when matching the intermediate content </dl>

(?:(?!</dl>)[\s\S])*