When using kotlin extension function, is it possib...

# android

[Samir Basnet]

When using kotlin extension function, is it possible to initialize some value inside the extension function only once ( like does lazy work inside extension function) and not create instance every time i call extension function??

[kenkyee]

No.. Think of them as the old static Util classes you had in Java

[Samir Basnet]

Ok . Also one more question is using a lot of extension functions bad? As they ultimately are static functions under the hood. So does it affect memory usages or any other performance hits?

[kenkyee]

Think of it as the Java Utils classes.... That's essentially what they are..

[Samir Basnet]

Yah i know that . But my question still exists

[kenkyee]

Overuse I'd say yes...that means you're not designing classes correctly

[kenkyee]

I.e. why did you need the extension function when you could have added it to the class

[Samir Basnet]

To reuse the function in different classes and keep my class code clean .

[gildor]

Well, you can do this by introducing top mutable property, used by the extension function

But usually it's not a good idea, it's shared mutable state, such code smells by definition, makes testing harder.
But if you have a good case for it, it's very easy to do

[Samir Basnet]

Thanks i used lazy val inside another Helper Object class and accessed it from my extension function to meet my usecase

[Lefko]

Great article

https://elizarov.medium.com/extension-oriented-design-13f4f27deaee

[gildor]

another Helper Object

You even don’t need another helper object, it can be a top level property