Sign Up

Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.

Have an account? Sign In

Have an account? Sign In Now

Sign In

Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.

Sign Up Here

Forgot Password?

Don't have account, Sign Up Here

Forgot Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

Have an account? Sign In Now

You must login to ask a question.

Forgot Password?

Need An Account, Sign Up Here

Please briefly explain why you feel this question should be reported.

Please briefly explain why you feel this answer should be reported.

Please briefly explain why you feel this user should be reported.

Sign InSign Up

The Archive Base

The Archive Base Logo The Archive Base Logo

The Archive Base Navigation

  • SEARCH
  • Home
  • About Us
  • Blog
  • Contact Us
Search
Ask A Question

Mobile menu

Close
Ask a Question
  • Home
  • Add group
  • Groups page
  • Feed
  • User Profile
  • Communities
  • Questions
    • New Questions
    • Trending Questions
    • Must read Questions
    • Hot Questions
  • Polls
  • Tags
  • Badges
  • Buy Points
  • Users
  • Help
  • Buy Theme
  • SEARCH
Home/ Questions/Q 102817
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Editorial Team
Asked: May 11, 20262026-05-11T01:01:31+00:00 2026-05-11T01:01:31+00:00

Regex.IsMatch( foo, [\U00010000-\U0010FFFF] ) Throws: System.ArgumentException: parsing [-] – [x-y] range in reverse order.

  • 0
Regex.IsMatch( 'foo', '[\U00010000-\U0010FFFF]' )  

Throws: System.ArgumentException: parsing ‘[-]’ – [x-y] range in reverse order.

Looking at the hex values for \U00010000 and \U0010FFF I get: 0xd800 0xdc00 for the first character and 0xdbff 0xdfff for the second.

So I guess I have really have one problem. Why are the Unicode characters formed with \U split into two chars in the string?

  • 1 1 Answer
  • 0 Views
  • 0 Followers
  • 0
Share
  • Facebook
  • Report

Leave an answer
Cancel reply

You must login to add an answer.

Forgot Password?

Need An Account, Sign Up Here

1 Answer

  • Voted
  • Oldest
  • Recent
  • Random
  1. 2026-05-11T01:01:32+00:00Added an answer on May 11, 2026 at 1:01 am

    They’re surrogate pairs. Look at the values – they’re over 65535. A char is only a 16 bit value. How would you expression 65536 in only 16 bits?

    Unfortunately it’s not clear from the documentation how (or whether) the regular expression engine in .NET copes with characters which aren’t in the basic multilingual plane. (The \uxxxx pattern in the regular expression documentation only covers 0-65535, just like \uxxxx as a C# escape sequence.)

    Is your real regular expression bigger, or are you actually just trying to see if there are any non-BMP characters in there?

    • 0
    • Reply
    • Share
      Share
      • Share on Facebook
      • Share on Twitter
      • Share on LinkedIn
      • Share on WhatsApp
      • Report

Sidebar

Ask A Question

Stats

  • Questions 74k
  • Answers 74k
  • Best Answers 0
  • User 1
  • Popular
  • Answers
  • Editorial Team

    How to approach applying for a job at a company ...

    • 7 Answers
  • Editorial Team

    How to handle personal stress caused by utterly incompetent and ...

    • 5 Answers
  • Editorial Team

    What is a programmer’s life like?

    • 5 Answers
  • added an answer Have you tried publishing the application (Build > Publish [app])?… May 11, 2026 at 2:32 pm
  • added an answer figured it out, did not see the connection string section.… May 11, 2026 at 2:32 pm
  • added an answer The problem is that the the HTTP protocol wrapper for… May 11, 2026 at 2:32 pm

Related Questions

Regex.IsMatch( foo, [\U00010000-\U0010FFFF] ) Throws: System.ArgumentException: parsing [-] - [x-y] range in reverse order.
This is one of the most used Regex functions Regex.IsMatch(Test text for regex test.,
I'm trying to create a Regex usuable in C# that will allow me to
I don't understand, why does the following regular expression: ^*$ Match the string 127.0.0.1?
Is it OK - best practise wise - to use the second layer to

Trending Tags

analytics british company computer developers django employee employer english facebook french google interview javascript language life php programmer programs salary

Top Members

Explore

  • Home
  • Add group
  • Groups page
  • Communities
  • Questions
    • New Questions
    • Trending Questions
    • Must read Questions
    • Hot Questions
  • Polls
  • Tags
  • Badges
  • Users
  • Help
  • SEARCH

Footer

© 2021 The Archive Base. All Rights Reserved
With Love by The Archive Base

Insert/edit link

Enter the destination URL

Or link to existing content

    No search term specified. Showing recent items. Search or use up and down arrow keys to select an item.