What is main reason for having `with` and `apply` ...

# getting-started

[Imany]

What is main reason for having with and apply ?

[StavFX]

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[Paul N]

apply is really useful for classes that have inappropriate constructors for your use.

Imagine you have a class with a zero arg constructor and you want to create it and immediately set some properties.

In Java, you'd do something like:

Animal dog = new Animal();
dog.setName("Fido");
dog.setColour("Black");

In Kotlin using apply:

val dog = Animal().apply {
name="Fido"
colour="Black"
}

With is handy when you have some properties of an object that you want to use, but you don't want to keep referring to the parent object:

Java:

Animal veryLongAnimalInstance = new Animal()

someMethod(veryLongAnimalInstance.getName(),veryLongAnimalInstance.getColour());

Kotlin:

veryLongAnimalInstance = Animal()
with(veryLongAnimalInstance) {
someMethod(name,colour)
}

[Martins Joseph]

@Paul N amazing and thanks for sharing