if - else

[Michael Geary]

Re: if - else

> > | if (10 == sum) {...}[color=blue][color=green]
> > |
> > | rather than
> > |
> > | if (sum == 10) {...}[/color][/color]
[color=blue][color=green]
> > Yes, there's such a style, and it's considered by experienced C
> > programmers to be as weird as if( (a<b) == TRUE )...[/color][/color]
[color=blue]
> Dunno about that, I've been using C since 1986 and every C
> project I've worked on since 1991 (about half a dozen biggish
> ones) has mandated the
>
> if (CONST == variable)...
>
> style of if statement check, and most of the recent books
> recommend it. So an awful lot of experienced C
> programmers use it day in day out - and I haven't heard
> any loud complaints.
> Generally anything that saves bugs in C is "A Good Thing",
> its like running lint - you just build it into the make rules
> so that you never forget...[/color]

The problem with "if( CONST == variable )" is that it reads unnaturally,
creating a mental speed bump when someone reads your code. Admittedly it's a
fairly minor speed bump, and avoiding coding errors is a good thing.
However, this contrivance is unnecessary with modern C compilers, which
issue a warning if you code "if( variable = CONST )".

With Microsoft Visual C++, I always set my project options so that warnings
are errors. If I code "if( variable = CONST )", it won't compile. Thus, I'm
able to use the more natural "if( variable == CONST )" notation without fear
of error.

It's certainly pleasant that Python sidesteps this issue completely! :-)

-Mike

[Jay O'Connor]

Re: if - else

Michael Geary wrote:
[color=blue][color=green][color=darkred]
>>>| if (10 == sum) {...}
>>>|
>>>| rather than
>>>|
>>>| if (sum == 10) {...}
>>>
>>>[/color][/color]
>
>
>[color=green][color=darkred]
>>>Yes, there's such a style, and it's considered by experienced C
>>>programmer s to be as weird as if( (a<b) == TRUE )...
>>>
>>>[/color][/color]
>
>
>[color=green]
>>Dunno about that, I've been using C since 1986 and every C
>>project I've worked on since 1991 (about half a dozen biggish
>>ones) has mandated the
>>
>>if (CONST == variable)...
>>
>>style of if statement check, and most of the recent books
>>recommend it. So an awful lot of experienced C
>>programmers use it day in day out - and I haven't heard
>>any loud complaints.
>>Generally anything that saves bugs in C is "A Good Thing",
>>its like running lint - you just build it into the make rules
>>so that you never forget...
>>
>>[/color]
>
>The problem with "if( CONST == variable )" is that it reads unnaturally,
>creating a mental speed bump when someone reads your code. Admittedly it's a
>fairly minor speed bump, and avoiding coding errors is a good thing.
>However, this contrivance is unnecessary with modern C compilers, which
>issue a warning if you code "if( variable = CONST )".
>
>[/color]

I was on a TCL project (ugh..one reason I don't use TKinter is simply
guilt by association...I learned to hate TCL on that project) where I
inherited code from a developer who did a lot of that "if 10==x" kinda
stuff. Basically we said the same thing; "it doesn't read naturally"

[color=blue]
> It's certainly pleasant that Python sidesteps this issue completely! :-)[/color]

True, but I'd still rather allow the assignment and catch the error by
not allowing boolean comparison of non-boolean values. This would break
a lot of other basic stuff in Python, though, such as using "if seq:" to
determine if a sequence is empty, but I've never been a big fan of that
shortcut (althuogh I use it myself). I'd rather the code have to be a
bit more explicit.