I'm sorry but I do not know what is happening. It might be something to do with your operating system or version of .net but I have no real idea. I can not reproduce this error
This is ChatGPTs best guess (it got confused about the character ❤ = $)
When you compile on a machine whose default “ANSI” code page isn’t UTF-8 (for example, Chinese Windows using GBK/CP936), that little red heart character (❤) in your .cs file actually becomes two bytes and thus two “characters” when the C# parser reads it as a character literal. That explains why on your machine (where your editor is probably saving the file as UTF-8) it shows up as one character, but on theirs it looks like two.
What’s happening under the hood
Character literal ('❤') in C# must be exactly one UTF-16 code unit.
In GBK/CP936, the heart glyph isn’t in the single‐byte table and is stored as a multi‐byte sequence.
When the compiler opens the file using the system ANSI code page, it sees two 8-bit values, thinks you wrote something like '\xXX\xYY', and complains “too many characters in character literal” (and “unexpected character …”).
Two easy fixes
Save the source as UTF-8 (with BOM)
In Visual Studio (or your editor), choose File → Save As → Save with Encoding → UTF-8 with signature (BOM).
This lets any Windows machine know “hey, this file is UTF-8,” so the compiler will read ❤ as one Unicode character.
Use an explicit Unicode escape or string
Replace your literal with one of these:
// As a char (single code‐unit)
char heart = '\u2764';
// Or as a string literal
string heart = "❤";
That way you don’t depend on file encoding or code pages at all.
