Why can Object be assigned a primitive value?

Question

Java

I always thought that reference types and primitive types could not be connected in any way, but I came across this absurdity:

public MagicClass{

 Object val = 12345; //да-да, вам не показалось, мы присваиваем ссылочному типу примитив!

 public void print(){ System.out.println(val); }

}

And here's how the compiler reacts:

12345

Process finished with exit code 0

Essence of the question : Why can we assign a primitive value to Objectint (And not only of type , but also of type double, etc.)?

Answer 1

During the execution of the construction Object val = 12345, a primitive value of the int type is auto -boxed into an object of the Integer type and its reference is assigned to the val variable. The latter is possible because Integer inherits from Object.