Hi there , what is difference between object and companion object in singleton pattern ? and what's ...

# android

[Mohamed Tamer]

Hi there , what is difference between object and companion object in singleton pattern ? and what's good way ? , Do both methods have no problem when using? !!!

[zsmb]

This Kotlinlang page describes the companion object's benefits over regular objects https://kotlinlang.org/docs/object-declarations.html#companion-objects

[zsmb]

Mostly that you can reference it by just the classname, e.g. Counter will point to it

[zsmb]

In your code examples though, you could just omit the nested object entirely, and make Counter itself an object, if you want it to be a singleton instance

[psh]

There is a subtle difference between the declarations in terms of object creation time -

object MySingleton {
}

and

class SomeClass {
    companion object {
    }
}

The companion object will get created when the first instance of SomeClass is created. In the case of the Kotlin singleton object, it will be created when it is first used.