6 ms·

I regularly see code of the form `if(x == false)` as the author has a distrust of `if(!x)`. I guess the author just distrusts smaller things, leaving me to dis

• ickyforce 4y ago
  This is completely another level of "issues" than other problems in this thread. During code review I'd only mention it as a nit. The longer form is correct and the only downside is that's a bit longer. It doesn't mess up code modularity or affect maintainability in a noticeable way. Well, assuming that the language doesn't have any quirks in this area - e.g. in Java your statements aren't equivalent for a Boolean x.
  • wizofaus 4y ago
    They're not equivalent in many languages (JS, C++/swift with operator overloads, if x is nullable etc. etc.).
  • kaba0 4y ago
    Nitpick (as in general you are right regarding java as well): I’m fairly sure they are the same for java in this instance. Both will convert Boolean to boolean, throwing an NPE if it was a null.
    • ickyforce 4y ago
      Ha, that's true, thanks! I guess my Java-fu is weak these days :)
• khalladay 4y ago
  It's been awhile since I absorbed the weird programming norm that "real programmers use the !x form!" but even after 10+ years of !x , I still find ==false more readable.
  • mcbutterbunz 4y ago
    I agree. To me, its simpler to understand. Suppose x is a bool, reading the code, I say to myself "if not true..." or "if not false..." and my ape brain gets confused on what happens if its not true or not false. Reading "if true == false" or "if false == false", it becomes much clearer what we're testing here and I understand it instantly.
    • linknoid 4y ago
      If the statement is "if (!isGreen)", it's much clearer to say "if is not green" than it is to say "if is green is false". Putting == true or == false makes you convert a clear statement "is green" into "true" or "false" instead of just being a natural English statement. It would be like saying in conversation, "I want to go to the store is false" instead of "I don't want to go to the store".
      • kcartlidge 4y ago
        > If the statement is "if (!isGreen)", it's much clearer to say "if is not green" than it is to say "if is green is false" I agree that when you read it, it's clearer. And yet I still prefer "if(isGreen == false)" for reasons of clarity in another sense. The "!" being right next to the "(" makes it easier to miss the "!" when scanning quickly through the code, hence reading the logic the wrong way round and seeing "(isGreen" instead of "(!isGreen". And that's enough of a risk to ignore the readability advantage of "(!". (Edit: To be clear, I don't suggest "== true" for the opposite cases, as the lack of a "!" in those means the risk is gone)
  • Banana699 4y ago
    Even if the not operator in the language you're writing in happens to be the actual word 'not' ?
    • khalladay 4y ago
      My whole career has been C++ and shader languages, so this really hasn't come up for me. I imagine it being a real word would improve readability greatly.
• BurningFrog 4y ago
  The worst one is "if x=true", which to me says the writer doesn't know what the if statement does... That said, if x is data read from elsewhere that just happens to be boolean, I can write code like that in Python.
• cozzyd 4y ago
  In some languages these do different things, right? (Or if someone did something horrendous with operator overloading)
• mmcgaha 4y ago
  As much as people push the more succinct if(x)/if(!x) style of expression, I don't know that it is better. Now if your example was if(is_a_thing) then maybe it reads better. Add to that the possibility of three value logic and I could lean more to the if(x == false) style.
• jon_richards 4y ago
  Some of that might be Python habits which is terrifying for completely different reasons.
• sodapopcan 4y ago
  I've seen this in Ruby and Elixir that drives me a little nuts: if !is_nil(foo)
  • lolc 4y ago
    While it may not matter in many circumstances, this is not the same as "if foo", because false is not nil.
    • sodapopcan 4y ago
      It's true but in 10+ years of writing Ruby it hasn't mattered in _any_ circumstances I've come across. I also assert that having a boolean where `nil` is meaningfully different than `false` is a smell and should be avoided.
• recursive 4y ago
  I wrote code like that sometimes. Equaling false is more specific, depending on language. There are many falsey things that are not false themselves.
• mmcnl 4y ago
  !x is not equal to === false.
• xorcist 4y ago
  Even more common seems to be if (x == true) which always seem to come with some argument how it is "more clear". I have started to ask people straight away to change to if ((x == true) == true) which following the same argument should be even more clear.
• pkamb 4y ago
  The UW intro CS courses call the `if (x)` form "Boolean Zen", which I've always enjoyed.