https://stackoverflow.com/questions/71546789/the-u-escape-sequence-in-c-sharp

CSharp · Console

/Program.cs

using System;

//https://stackoverflow.com/questions/71546789/the-u-escape-sequence-in-c-sharp
					
public class Program
{
	public static void Main()
	{
		// These compile because they're valid Hex numbers in the range 000000 - 10FFFF padded to 8 digits with leading zeros:
		Console.WriteLine("\U0001F47D");
		Console.WriteLine("\U00000000");
		Console.WriteLine("\U0010FFFF");
		// But these don't.
		// H is not a valid Hex character:
		// Compilation error (line 16, col 22): Unrecognized escape sequence
		Console.WriteLine("\U00HHHHHH");
		// This is outside the range of 000000 - 10FFFF:
		// Compilation error (line 19, col 22): Unrecognized escape sequence
		Console.WriteLine("\U001effff");
	}
}