Why signed char

This is due to the reason that char type technically stores integers and not characters. It makes use of a numerical code which represents characters by using integers. For example — ASCII code which is one of the most commonly used codes for carrying out such interpretations. C90 enabled C to use keywords signed and unsigned with char. It is important to note that they are only used when small integer values are to be handled. Signed char and unsigned char are both of 8 bit bytes on a 16 bit machine.

They primarily differ in the range represent by them. The range of unsigned char is 0 to , whereas the size of char or signed char is to The transformation of char into int values is done automatically by C. Aside from that, I can think of two main cases where char sign matters:. The nasty thing is, these won't bite you if all your string data is 7-bit. Signedness works pretty much the same way in char s as it does in other integral types.

As you've noted, chars are really just one-byte integers. Not necessarily 8-bit , though! There's a difference; a byte might be bigger than 8 bits on some platforms, and char s are rather tied to bytes due to the definitions of char and sizeof char.

To the compiler, char s are bytes and vice versa, and it doesn't distinguish between them. Sometimes, though, you want to -- sometimes you want that char to be a one-byte number, and in those cases particularly how small a range a byte can have , you also typically care whether the number is signed or not.

I've personally used signedness or unsignedness to say that a certain char is a numeric "byte" rather than a character, and that it's going to be used numerically. Without a specified signedness, that char really is a character, and is intended to be used as text. I used to do that, rather. The only situation I can imagine this being an issue is if you choose to do math on chars.

It's perfectly legal to write the following code. Depending on the signedness of the char, c could be one of two values. If char's are unsigned then c will be char If they are signed then it will an overflow case as the max value for a signed char is I'm guessing most implementations would just return char Of course, it's not portable, so not very useful.

Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. What does it mean for a char to be signed? Ask Question. Asked 12 years, 10 months ago. Active 5 years, 5 months ago. Viewed 40k times. Improve this question. Prince Add a comment. Active Oldest Votes. Improve this answer. Nick Fortescue Nick Fortescue He's saying there's no type called byte , not that no type is a byte.

If the char type is signed , then it can contain 0 , negative , and positive values , and its minimum range as defined by the C standard , is between , and Beside the char type in C , there is also the unsigned char , and the signed char types. All three types are different , but they have the same size of 1 byte. The unsigned char type can only store nonnegative integer values , it has a minimum range between 0 and , as defined by the C standard.

The signed char type can store , negative , zero , and positive integer values. It has a minimum range between and , as defined by the C standard. A character literal , is formed of a character , such as a , enclosed in single quote.

A character literal can contain escape sequences. An escape sequence , is used as a way to represent characters , in the execution character set. For example a new line , that must appear on a console , or on the terminal.