A single character may be written as a single quote immediately followed by that character. Some backslash escapes apply to characters, \b , \f , \n , \r , \t , and \" 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.