A single character may be written as a single quote immediately followed by that character. Some backslash escapes apply to characters,
\" with the same meaning as for strings, plus
\' for a single quote. So if you want to write the character backslash, you must write '\\ where the first
\ escapes the second
\. As you can see, the quote is an acute accent, not a grave accent. A newline immediately following an acute accent is taken as a literal character and does not count as the end of a statement. The value of a character constant in a numeric expression is the machine’s byte-wide code for that character.
as assumes your character code is ASCII: 'A means 65, 'B means 66, and so on.