"Cesar Rabak" <csrabak@yahoo.com.br> wrote in message 
news:eoj0u8$148$1@aioe.org...
> Ludovic Brenta escreveu:
>> Jean-Pierre Rosen a �crit :
>>>> A question: I see all the time things like "if (.. < ..)" in C - are 
>>>> the
>>>> parentheses required there ?
>>> Yes, they are - because C has no "then" keyword. There must be something
>>> to tell the compiler where the expression ends...
>>
>> Not to mention that the parentheses may contain several expressions
>> separated by the comma operator, some or all of which may have side
>> effects, and only the last of which actually controls the if
>> statement... for example:
>>
>> if (a = 1, b = a, c = --a, (a = --b) == c) {
>>    ...
>> }
>>
>> Ah, the joy of obfuscated programming :) :) :)
>>
> Would you believe that:
>
> if (a = 1) {
>     ...
> }
>
> Is semantically valid C, but because it is very easy to mistake this when 
> the intended was:
>
> if (a == 1) {
>     ...
> }
>
> That there are tools to look for and signal this!?

A lot of C compiler will warn you about constructs such as

    if (a=1) {
        ...
    }