Regular expression not null c#

These constructs include the language elements listed in the following table. For more information, see Alternation Constructs. Substitutions are regular expression language elements that are supported in replacement patterns. For more information, see Substitutions.

The metacharacters listed in the following table are atomic zero-width assertions. You can specify options that control how the regular expression engine interprets a regular expression pattern. Many of these options can be specified either inline in the regular expression pattern or as one or more RegexOptions constants. This quick reference lists only inline options.

For more information about inline and RegexOptions options, see the article Regular Expression Options. Miscellaneous constructs either modify a regular expression pattern or provide information about it. The following table lists the miscellaneous constructs supported by. For more information, see Miscellaneous Constructs. Skip to main content. This browser is no longer supported.

Download Microsoft Edge More info. Contents Exit focus mode. Is this page helpful? Please rate your experience Yes No. Any additional feedback? It can be preceded and followed by anything, any character or whitespace sequence including new lines :. You can try it with explanation on regex Most regular expression engines support "counter part" escape sequences. Stack Overflow for Teams — Collaborate and share knowledge with a private group.

Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Regex for not empty and not whitespace Ask Question. Asked 10 years, 2 months ago. Active 9 months ago. Viewed k times. James A Mohler You can use str. NarendraYadala, this will not match on tabs and other whitespace characters. Add a comment. Active Oldest Votes. In some languages e. Hi Friends I need a reguler expression that allows: 1 blank or empty 2 decimal values 3 integer values C.

Copy Code. Posted Aug am deepakaitr Updated Aug am Yvan Rodrigues. Add a Solution. Top Rated Most Recent. Accept Solution Reject Solution. You have the Required attribute on there. If a value is required it cannot be null. The regular expression has nothing to do with it. Posted Aug am fjdiewornncalwe. So, you allow I assume with leading and trailing spaces 1. Posted Aug am Andreas Gieriet. Regular expression pattern for allowing null and empty Ask Question.

Asked 5 years, 9 months ago. Active 5 years, 9 months ago. Viewed 9k times. I want null or empty to be accepted. Improve this question. Kranthi Sama Kranthi Sama 1 1 gold badge 10 10 silver badges 27 27 bronze badges. Notice the alteration which will allow blank or empty string. Note that a regex operates on text and cannot determine a null value, only an empty string.