Why does this code show the negative value?

Question

I suspect it has something to do with signed and unsigned, but, why does it show -23 instead of 23?
https://code.sololearn.com/czOx12ksBB5l/?ref=app

Answer 1

<i> is an unsigned int, and <c> is a signed int. When you compare two integral values with different sign, the RHS operand will silently be converted to the same type of LHS. In your case, your condition `if(i > c)` evaluates to false, because during the comparison, <c> is converted from signed int to unsigned int. To understand what I mean try `printf("%u", c);` this will show you why a 23 (as unsigned int) is considered less than -23 (as unsigned int).

Hth, cmiiw

Answer 2

-23 as unsigned int = 4294967273
Binary or not, 23 is less than that big value : )

Answer 3

Thank you so much! I got it from the C challenges in SL. It was a very tricky question for me. I guess we can learn something everyday!

Answer 4

Thank you also, yes there's always a new thing to learn everyday : )