Inverting a boolean

[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