Multibyte Integers Variables in C

Question

I'd like to know, how to calculate integer values of strings in single quotes ' '.

My sample code is:

#include <stdio.h>

int main()
{
    int c = 'aA';
    int d = 'Aa';

    printf( "%d %d" , c, d);

    return 0;
}

And the output is:

24897 16737

What are those numbers? Is there any formula to calculate them ?

@Nick No, they aren't. **But:** what OP has is valid, it just means something different. — , Nov 14 '12 at 18:22
At one time, this was closed as a duplicate of [What do single quotes do in C++ when used on multiple characters?](http://stackoverflow.com/questions/7459939/what-do-single-quotes-do-in-c-when-used-on-multiple-characters) Given that the alternative is a C++ question and this is C, it is not altogether surprising that someone objected and removed the duplicate information — but the fact that it was marked as a duplicate is still recorded. Not sure what to do best, but at least you don't have to go hunting through the edit history to find the purported duplicate. — Jonathan Leffler, Jul 25 '15 at 07:03

score 5 · Accepted Answer · 2012-11-14T18:26:30.230

These are:

not strings!
multibyte integers, of which the value is implementation-defined, but it is usually calculated using this formula:

integer value of 1st character multiplied by (2 << CHAR_BITS) + integer value of 2nd character

So, assuming your C locale uses ASCII and you have 8-bit bytes, 'aA' becomes

97 * 256 + 65

which is 24897.

Multicharacter literals are of type int.

score 2 · Answer 2 · answered Nov 14 '12 at 18:16

2

It is the value of multi-character character stored in your variables

answered Nov 14 '12 at 18:16

Durairaj Packirisamy

4,635
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score 1 · Answer 3 · answered Nov 14 '12 at 18:24

The value of a multi-character constant is implementation-defined.

§ 6.4.4.4 Character constants
The value of an integer character constant containing more than one character (e.g., 'ab'), or containing a character or escape sequence that does not map to a single-byte execution character, is implementation-defined.

Multibyte Integers Variables in C

3 Answers3

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