C＃：正则表达式为2和/或3个单词的名称

Question

In my C# app, user enters a name. I want to set a Regex where user can enter only 2 or 3 words ie "John Brandy" or "John Brandy Paul". And each word not less than 2 and greater than 15 chars.

Match match = Regex.Match(str, @"^[A-Z]+ [A-Z]+ [A-Z]+$", RegexOptions.IgnoreCase); // @"^\b[a-zA-Z]{2,15}\s[a-zA-Z]{2,15}\b");  //@"(\w)\s(\w){2, 3}");
Console.WriteLine("PAttern Success = " + match.Success);

With the current pattern, I got to enter 3 words.

Answer 1

Another idea to use a quantified group .

^(?:[A-Z]{2,15} ?\b){2,3}$

• use with your RegexOptions.IgnoreCase
• the \\b stands for word boundary .

See demo at regex101

Answer 2

You can use the ? to match zero and once, along with the pattern in your comment.

^[a-zA-Z]{2,15}\s[a-zA-Z]{2,15}(?:\s[a-zA-Z]{2,15})?$

Live Demo

Additionally the ?: tells that it should be a non-capturing group.

Note that \\s also matches newlines, so you might instead want [ \\t] . If you want to allow multiple spaces then use [ \\t]+ .

Answer 3

试试这个它应该工作。

^[a-zA-Z]{2,15}\\s([a-zA-Z]{2,15}\\s)?[a-zA-Z]{2,15}$

Answer 4

^(?:[AZ][A-Za-z]{2,15} ?\\b){2,3}$无需使用IgnoreCase即可工作