[NSRCA-discussion] Chapter-12 computer science.

[Martin X. Moleski, SJ]

Duane Beck wrote:

> Depends on whether char basic type is 8-bit or larger.  Most decent 
> compilers should issue a warning for comparing with an integer constant 
> out of range.  Assuming default char type is 8-bit signed, when cnt is 
> 127, cnt increments to -128 (by wrapping around adjacent two's 
> complement values) and the loop continues unterminated.  If default char 
> type is 8-bit unsigned, it's still unterminated because after 255, cnt 
> will increment to 0.  So, in both conditions, cnt is always less than 
> 256.

I'm with you up to here--I missed the significance
of knowing what type of var cnt is.

>   Otherwise, if char is larger (16-bit), foo returns 256.

Seems to me that if the loop terminates,
num has to be 255.  cnt and num are both
initialized to 0 and incremented under
the same conditions (cnt < 256).  I don't
seem how num can get beyond 255 when
starting with cnt from 0.

			Marty


> 
> Duane
> 
> Martin X. Moleski, SJ wrote:
>> John Pavlick wrote:
>>> OK, what does this do?
>>> char foo(void)
>>> {
>>>      char cnt, num;
>>>
>>>     for(cnt = 0, num = 0; cnt < 256; cnt++)
>>>     {
>>>          num++;
>>>     }
>>>     return num;
>>> }
>>
>> Initializes cnt and num to 0.
>>
>> Increments cnt and num from 0 to 255
>> by passing through the for loop.
>>
>> Returns 255.
>>
>>
>> 			Marty
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