Personal preference, I always go for "== false" if for one reason only... My
eye sometimes misses a single "!"

definatley the first one. it's much easier to read.

It just comes down to personal preference and which you find easier to read.
I personally use the latter but can read either one just fine.  Those
unfamiliar with C# will find the first easier to understand, but when seeing
it they will have no motivation to learn anything more about C#.

My opinion is it's generally best not to dictate things that come down to
personal style choices when it is as simplistic as your example.  There is
no strong justifiable reason to force anyone to use one syntax over the
other.

Hi Anders,

Using the ! character is safer in case you accidentally forget an = character:

bool aBool = false;

if (aBool = false)
{
   // aBool was false, but this code won't execute
   // Worse even, the compiler allows it
}

Although, the compiler does give a nice warning :)

Slightly OT, but we had a similar discussion in the days of ye-olde
ASP, on which of the following was more efficient.

This one:
If <condition> Then
 var = 1
Else
 var = 2
End If

Or this one:
var = 2
If <condition> Then var = 1

Imagine how heated that got when I threw IIF() into the pot, for fun.
By the way, the outcome was much the same as this one.

Anders,

Why not

if (DetermineResultFromMethod(arg1, arg2) != true)) {}

<g>

No seriously I tend to use !

Mattias

If I'm treating the boolean as a *condition* (which is the usual case)
I'll use if (!condition)

That way when I read it it's: "if not condition" which makes more sense
to me than "if condition equals false".

If it's a "value" in itself (and I'm struggling to even think of any
examples here) then I'd probably be okay with if (value == false).

I think the risk with the "== false" approach is that you might be tempted to
start coding "== true" to be consistent and that would just be redundant
(then you'd read your boolean conditions as "if it's true that x is true"...).

Hi Anders,

Interesting thread.

Personally, I just use ! everywhere because I think it's quite easy to
understand, it only takes one key press, it's not going to accidentally assign
a value, and contrary to what other respondents have written, I don't think
that it's hard to miss at all.  As a matter of fact,  I never place a space
between the ! and the predicate in real code either, and I don't remember ever
exclaiming, "My code wasn't working as I expected, but then I realized that I
didn't see the !" ;)

"false ==" and "== false" just looks sloppy to me for some reason, the latter
may be subject to accidental assignment with only a compiler warning and it's
more to type.  Although, I agree that reading "== false" as, "if condition is
false" might make more sense than reading it as, "if not true", but that's not
the deciding factor for me.  "false ==" is not readable at all, but is
recommended to prevent accidental assignment in certain situations.
Therefore, it makes sense to use ! in certain situations and then, for the
sake of consistency, all situations.  The value of consistency here may be
arguable though.

I am all for the use of the ! operator.

The reason is that ==false and ==true gives me associations about
very inexperienced programmers.

Arne

what the code is shorter,the coder is smarter:)

So... all in all, seems I was outnumbered 10-1!
Go for the "!"