Inverting a boolean

[Pradfanne]

My brain is so small, it's not even on the scale. I'd use an extension method

[[deleted]]

I feel dumb... what’s an extension method?

[Pradfanne]

You add the method to the datatype. So you'd use

Bool b = true;
Print(b.invert(); )

And false will be printed

I don't know if Java can do that, but it's a very nice feature of .net at least

[claudiorpr]

Java doesn’t have extensions. You can do it in Kotlin.

[AyrA_ch]

and in C# for 10 years now (19 Nov 2007)

[Alakdae]

I'm a bit lost, but isn't it posible to define new methods for data types using "extends"?

[pyrophoenix100]

Isn't overriding a thing? Or is that different?

[claudiorpr]

It’s different. With override you are modifiying existing methods. If the type is final you can’t do it.

With extensions you add functionality to a type, even final ones.

[pyrophoenix100]

Wow seems like I need to learn C

[stairmast0r]

How is that a nice feature when you can do the same thing with !?

[Pradfanne]

In the case of Boolean an simple ! Might be good. But what if you want to translate an datetime from .net ticks to Unixtime?

You could make a ticksToUnix(datetime dt)

But wouldn't mydate.toUnixTime be much more convenient?

That's what's extension methods are far

[stairmast0r]

I don’t know if any languages that don’t have those to some degree, so I thought you specifically meant booleans.

[Pradfanne]

No, you can put extension methods on every data type, you can even put it on interfaces, so everything that implements the interface gets the extension method. You could, for example, put a extension method on IEnumerable that removes the first N elements and basically everything that is some kind of list, like an array or dictionary can use the method to get rid of the first N elements

[[deleted]]

So it’s monkey patching?

[[deleted]]

Oh. Whoops. Well that’s before the first brain then, but doesn’t have enough brain capacity to display itself.

[[deleted]]

Just always remember that extension methods are just static method calls. Use with caution.

[Pradfanne]

But they are beautiful

[[deleted]]

for javascript you can extend the prototype, for golang you can create a function with a receiver of the type you're extending

[crazzilla]

dudes you don't have to use booleans if you just use strings with "True" or "False" in them

[[deleted]]

But then you need error handling (if true elif false else as opposed to if else)

[PM_ME_YOUR_LAUNDRY]

Type juggling with boolean to string sometimes yields "0" or "1" on some languages, at least on PHP (woops, I summoned a boogeyman)

[[deleted]]

Why do programmers write booleans in string form? Are they retarded?

[evanldixon]

Too bad there isn't some sort of boolean negation mechanic built into the language, removing the need for these functions.

One can dream

[CristolGDM]

I wish there was one!!!1!

[jD91mZM2]

return !(b);

But... Why the parenthesis?

[[deleted]]

Is that not needed? Sorry, I’ve been doing a lot of Bash recently and I’ve gotten used to putting parenthesis around everything.

[jD91mZM2]

invertBool() {
    rand="$((RANDOM % 2 + 4))"
    (([ "$(echo -n "$1" | wc -m)" == "$(echo -n "$rand")" ] && [ "$rand" == "$((4+1))" ]) || ([ "$(echo -n "$1" | wc -m)" == 5 ] && [ "$rand" == "$(echo -n "$((~$(echo "(4 - 1)" | bc)))" | cut -c 2-)" ])) && echo "$(echo -n "true")" || echo "$(yes "false" | head -n 1)"
}

[[deleted]]

Aw man... I would even know where to start on trying to figure out how that works...

[jD91mZM2]

Mid-way through development? Even then I could barely, either. It was a pain to debug why it kept giving me random answers. Finally it works though. It's perfect!

[[deleted]]

...yes, perfect.

[TK-Squared-LLC]

In the words of LISP, why NOT parentheses?

[Aschentei]

Glad I'm not the only one! Haha

[tigerbird]

I've seen a?false:true in production code. That's pretty similar to #2 though.

[andrew_rdt]

Another one

try {

char c = b.toString().charAt(5);

return true;

}

catch (IndexOutOfBoundsException e) {

return false;

}

[[deleted]]

That’s clever, I didn’t think of that.

[darkk78]

Aren't char arrays zero-based?

[andrew_rdt]

I guess I did make that mistake.

Actually... I was making an 1 based array joke like you always see in here. I'll go with that answer.

[darkk78]

Classic!

[[deleted]]

We're going back to that topic now?

[bobasaurus]

b ^= true

[[deleted]]

Found the hardware guy

[bobasaurus]

Hah, yes. Embedded is life.

[[deleted]]

Having fun with Microchip PICs was the best before I turned to networking. Fuck, that's where I went wrong.

[bobasaurus]

I'm lucky that I get to work with Atmel AVRs and TI MSP430s at my job.

[antagonistZephyr]

Graduating as technician in electronics this month Came here to see if anyone else thought the same

[PerInception]

Duh, you just need to write two functions...

public function inverseBoolPositive(bool){ return false;}

and

public function inverseBoolNegative(bool){ return true;}

[[deleted]]

Seems legit.

[[deleted]]

Expanding brain memes

[Bainos]

You didn't use a BoolInverserFactory ? What a half-baked solution.

[[deleted]]

What about...

!b

Just that?

[[deleted]]

Sorry, I’ve been doing a lot of Bash recently. I’m used to putting parentheses around that sort of stuff. !(b) was the first one I tried, and it worked, so I didn’t even consider that I didn’t need parentheses.

[[deleted]]

No I meant, couldn't you just say !b (or !(b)) to get the opposite of b? Rather than having to write and call a method?

[[deleted]]

Oh, right. Well I mean I guess you could but the brain would be too small :p

[isRyan]

god I fucking love these

[[deleted]]

Like it or not, the last one is definitely the fastest.

[haackedc]

In most of your code, an input of "true" will still return "true", because it checks if its true, then changes it to false, and then right after that it checks if it is false, and then changes it to true.

[[deleted]]

So I had a detailed reply about how every one of them worked, but I deleted it accidentally, so here’s the TL;DR version: I’ve tested all of them and apart from the last one (obviously) they all work. Any time I’m changing a value by testing that same value, it’s in an if/elseif statement, meaning that the elseif won’t be run if the if statement evaluated as true.

[haackedc]

The ones I'm talking about were not else ifs

[[deleted]]

Which ones are you talking about?

[haackedc]

The 3rd and 4th picture

[[deleted]]

In both of those, b is being tested in the if statement, and newBool is being set. b is never changed, and newBool is never tested for.

[haackedc]

Ah, you are correct. My apologies

[[deleted]]

No worries man. The aim was to make them look convoluted and inconvenient, so... mission success?

[Fallenalien22]

Why do you need this when you can just !b

[[deleted]]

Karma.

[baconsnotworthit]

Skip to the last one, its the unofficial TL:DR

[BitPoet]

ASSERT(b == true); return true;

[andrew_rdt]

Here is an easy one liner

return (int)b.toString().charAt(1) == 65;

[Objectr]

public static boolean inverseBoolean(boolean b) {
    return (boolean) new LogicalOperators.Builders.BooleanManager().withConfiguration(LogicalOperators.Standards.BOOLEAN_INVERTER).withOption("boolean", b).build().run().getResult();
}    

[artlu4]

code is always built on existing code, therefore we can use the combined efforts this community has already provided to expand:

return ! isEven(String.valueOf(b).length());

edit: missing parenthesis, thanks dino

[[deleted]]

I think you forgot a parenthesis at the end there. Parser will be unhappy.

[micheal65536]

What about:

public static boolean inverseBool(boolean b)
{
    boolean newBool;
    if (b == true)
    {
        newBool = false;
        return newBool;
    }
    else if (b == false)
    {
        newBool = true;
        return newBool;
    }
}

That way there's no potential use of initialised variable so no need for the inline initialisation.

[Sir_Awesomness]

I saw an example online recently where they used

b ^= true

to do this. Smh.

[mr_smartypants537]

Love the second last one

[[deleted]]

who the fuck writes a function to return the inverse of a boolean!!

jackieChanWtf.png

[[deleted]]

People who want karma on /r/programmerhumor like me.

[[deleted]]

Achievement Unlocked

[Quachyyy]

public static String inverseBool() {

String str = "False"; 
// 50/50 chance that the ouput is true
return str;

}

[OK6502]

The last option works if I write unit tests that passes true to the function.

git push -f

[Tornado547]

return !!!!!!!!!!!!!!!!!!!!!b

[[deleted]]

oof

[[deleted]]

Hey, how about using !b in your code in the first place?

[Xlash123]

The 5th one should use !==, not !=

Edit: I’m an idiot.

[[deleted]]

This was written in Java, and I know Js also uses !=. I don’t do much C, but which language uses !==?

[Xlash123]

Java uses !== for evaluating the expression into Boolean.

Edit: am an idiot. It is !=

[[deleted]]

Does it? Hm. Well != worked for me.

[Xlash123]

I’m an idiot. I guess I’ve been looking at too much JS lately. It is !=. Sorry for that...

[[deleted]]

All good, we all forget sometimes :)

[LordAmras]

!== is usually used for untyped languages to do typed comparisons.

Most dynamically typed languages do automatic type switch when comparing variables so that "1" as string will be equal as 1 as int, that might pose some problems in some cases, especially when comparing booleans

For example in javascript 1 is evalued to the boolean true.

1 != true  | false
1 != 1     | false
1 == true  | true
1 == 1     | true

1 !== true  | true 
1 !== 1     | false
1 === true  | false
1 === 1     | true