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Re: unsigned == signed ?

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On Tue, 11 Oct 2011 19:43:03 +0000, Raj Pashwar wrote:
> int main()
> {
> uint x = -1;
> int y = -1;
> if (x == y)
> printf("EQUAL");
> else
> printf("NOT EQUAL");
> }
> 
> This code prints "EQUAL". Does this mean that bit comparison is done for
> the
> equality test? If it doesn't can you give me an example that shows bit
> comparison isn't done?

no ! unsigned int, and signed int are very different the way they are
represented in bits. therefore, when you to compare the 2 different types
(like comparing apples and oranges) one of them has to be converted, in 
this
case, the 'int' is converted to a 'uint', and becomes 0, since unsigned
numbers cannot be less then zero.
and besides, the == operator it *not* a bit comparison operator, it is a
variable comparison operator, if you want to do bit comparison you use the
bitwise operators, &,|,^,~. (and, or, exclusive or, not. respectively) 

> I also wanted to know if we can assign a number
> to uint & int variables such that "unit var != int var". Thanks so much

yes, if unit var = 1, and int var is any value other than 1 (-1, 0, -10, 
10,
100, whatever) then they will be 'not equal' if you use the operator '!='
for example:

uint x = 1;
int y = -1;
if (x == y)
    printf("EQUAL");
 else
    printf("NOT EQUAL");

will print NOT EQUAL since y is converted to an unsigned int and becomes 
0 

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unsigned == signed ? Raj Pashwar <raj121190@hotmail.NOSPAM.com> - 2011-10-11 19:43 +0000
  Re: unsigned == signed ? Keith Thompson <kst-u@mib.org> - 2011-10-11 12:57 -0700
  Re: unsigned == signed ? James Kuyper <jameskuyper@verizon.net> - 2011-10-11 16:23 -0400
  Re: unsigned == signed ? Quentin Pope <qp19433@hotmail.NOSPAM.com> - 2011-10-11 20:33 +0000
    Re: unsigned == signed ? James Kuyper <jameskuyper@verizon.net> - 2011-10-11 16:40 -0400
    Re: unsigned == signed ? Keith Thompson <kst-u@mib.org> - 2011-10-11 14:34 -0700
      Re: unsigned == signed ? Quentin Pope <qp19433@hotmail.NOSPAM.com> - 2011-10-12 16:04 +0000
        Re: unsigned == signed ? Keith Thompson <kst-u@mib.org> - 2011-10-12 10:49 -0700
        Re: unsigned == signed ? pete <pfiland@mindspring.com> - 2011-10-12 21:12 -0400
    Re: unsigned == signed ? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-11 22:35 +0100
      Re: unsigned == signed ? Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-10-13 14:54 +0300
        Re: unsigned == signed ? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-13 15:26 +0100
    Re: unsigned == signed ? "J. J. Farrell" <jjf@bcs.org.uk> - 2011-10-12 03:02 +0100
  Re: unsigned == signed ? Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-10-13 13:56 +0300

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